## error – unable to connect to the administrator after an apparently successful installation

``````There has been an error processing your request
Exception printing is disabled by default for security reasons.
Error log record number: 363200370184
``````

So I investigated `363200370184`

``````{"0":"Image CAPTCHA requires GD extension","1":"#1 Magento\Captcha\Model\DefaultModel->__construct(&Magento\Backend\Model\Auth\Session\Interceptor#000000007de0b08f0000000016f2016c#, &Magento\Captcha\Helper\Adminhtml\Data#000000007de0b2190000000016f2016c#, &Magento\Captcha\Model\ResourceModel\LogFactory#000000007de0b21f0000000016f2016c#, 'backend_login', NULL) called at (vendor/magento/framework/ObjectManager/Factory/AbstractFactory.php:111)n#2 Magento\Framework\ObjectManager\Factory\AbstractFactory->createObject('Magento\Captcha\...', array(&Magento\Backend\Model\Auth\Session\Interceptor#000000007de0b08f0000000016f2016c#, &Magento\Captcha\Helper\Adminhtml\Data#000000007de0b2190000000016f2016c#, &Magento\Captcha\Model\ResourceModel\LogFactory#000000007de0b21f0000000016f2016c#, 'backend_login', NULL)) called at (vendor/magento/framework/ObjectManager/Factory/Dynamic/Developer.php:66)n#3 Magento\Framework\ObjectManager\Factory\Dynamic\Developer->create('Magento\Captcha\...', array('formId' => 'backend_login')) called at (vendor/magento/framework/ObjectManager/ObjectManager.php:56)n#4 Magento\Framework\ObjectManager\ObjectManager->create('Magento\Captcha\...', array('formId' => 'backend_login')) called at (vendor/magento/module-captcha/Model/CaptchaFactory.php:37)n#5 Magento\Captcha\Model\CaptchaFactory->create('DefaultModel', 'backend_login') called at (vendor/magento/module-captcha/Helper/Data.php:100)n#6 Magento\Captcha\Helper\Data->getCaptcha('backend_login') called at (vendor/magento/module-captcha/Observer/CheckUserLoginBackendObserver.php:53)n#7 Magento\Captcha\Observer\CheckUserLoginBackendObserver->execute(&Magento\Framework\Event\Observer#000000007de0b2620000000016f2016c#) called at (vendor/magento/framework/Event/Invoker/InvokerDefault.php:88)n#8 Magento\Framework\Event\Invoker\InvokerDefault->_callObserverMethod(&Magento\Captcha\Observer\CheckUserLoginBackendObserver#000000007de0b2450000000016f2016c#, &Magento\Framework\Event\Observer#000000007de0b2620000000016f2016c#) called at (vendor/magento/framework/Event/Invoker/InvokerDefault.php:74)n#9 Magento\Framework\Event\Invoker\InvokerDefault->dispatch(array('instance' => 'Magento\Captcha\...', 'name' => 'captcha'), &Magento\Framework\Event\Observer#000000007de0b2620000000016f2016c#) called at (vendor/magento/framework/Event/Manager.php:66)n#10 Magento\Framework\Event\Manager->dispatch('admin_user_authe...', array('username' => 'shinta', 'user' => &Magento\User\Model\User\Interceptor#000000007de0b2770000000016f2016c#)) called at (generated/code/Magento/Framework/Event/Manager/Proxy.php:95)n#11 Magento\Framework\Event\Manager\Proxy->dispatch('admin_user_authe...', array('username' => 'shinta', 'user' => &Magento\User\Model\User\Interceptor#000000007de0b2770000000016f2016c#)) called at (vendor/magento/module-user/Model/User.php:631)n#12 Magento\User\Model\User->authenticate('shinta', 'xxxxxxxxxx') called at (generated/code/Magento/User/Model/User/Interceptor.php:193)n#13 Magento\User\Model\User\Interceptor->authenticate('shinta', 'xxxxxxxxxx') called at (vendor/magento/module-user/Model/User.php:687)n#14 Magento\User\Model\User->login('shinta', 'xxxxxxxxxx') called at (generated/code/Magento/User/Model/User/Interceptor.php:219)n#15 Magento\User\Model\User\Interceptor->login('shinta', 'xxxxxxxxxx') called at (vendor/magento/module-backend/Model/Auth.php:156)n#16 Magento\Backend\Model\Auth->login('shinta', 'xxxxxxxxxx') called at (vendor/magento/framework/Interception/Interceptor.php:58)n#17 Magento\Backend\Model\Auth\Interceptor->___callParent('login', array('shinta', 'xxxxxxxxxx')) called at (vendor/magento/framework/Interception/Interceptor.php:138)n#18 Magento\Backend\Model\Auth\Interceptor->Magento\Framework\Interception\{closure}('shinta', 'xxxxxxxxxx') called at (vendor/magento/framework/Interception/Interceptor.php:153)n#19 Magento\Backend\Model\Auth\Interceptor->___callPlugins('login', array('shinta', 'xxxxxxxxxx'), array(array('security_admin_s...'))) called at (generated/code/Magento/Backend/Model/Auth/Interceptor.php:78)n#20 Magento\Backend\Model\Auth\Interceptor->login('shinta', 'xxxxxxxxxx') called at (vendor/magento/module-backend/App/Action/Plugin/Authentication.php:205)n#21 Magento\Backend\App\Action\Plugin\Authentication->_performLogin(&Magento\Framework\App\Request\Http#000000007de0b1eb0000000016f2016c#) called at (vendor/magento/module-backend/App/Action/Plugin/Authentication.php:157)n#22 Magento\Backend\App\Action\Plugin\Authentication->_processNotLoggedInUser(&Magento\Framework\App\Request\Http#000000007de0b1eb0000000016f2016c#) called at (vendor/magento/module-backend/App/Action/Plugin/Authentication.php:125)n#23 Magento\Backend\App\Action\Plugin\Authentication->aroundDispatch(&Magento\Backend\Controller\Adminhtml\Index\Index\Interceptor#000000007de0b3380000000016f2016c#, &Closure#000000007de0b3300000000016f2016c#, &Magento\Framework\App\Request\Http#000000007de0b1eb0000000016f2016c#) called at (vendor/magento/framework/Interception/Interceptor.php:135)n#24 Magento\Backend\Controller\Adminhtml\Index\Index\Interceptor->Magento\Framework\Interception\{closure}(&Magento\Framework\App\Request\Http#000000007de0b1eb0000000016f2016c#) called at (vendor/magento/framework/Interception/Interceptor.php:153)n#25 Magento\Backend\Controller\Adminhtml\Index\Index\Interceptor->___callPlugins('dispatch', array(&Magento\Framework\App\Request\Http#000000007de0b1eb0000000016f2016c#), NULL) called at (generated/code/Magento/Backend/Controller/Adminhtml/Index/Index/Interceptor.php:39)n#26 Magento\Backend\Controller\Adminhtml\Index\Index\Interceptor->dispatch(&Magento\Framework\App\Request\Http#000000007de0b1eb0000000016f2016c#) called at (vendor/magento/framework/App/FrontController.php:55)n#27 Magento\Framework\App\FrontController->dispatch(&Magento\Framework\App\Request\Http#000000007de0b1eb0000000016f2016c#) called at (vendor/magento/framework/Interception/Interceptor.php:58)n#28 Magento\Framework\App\FrontController\Interceptor->___callParent('dispatch', array(&Magento\Framework\App\Request\Http#000000007de0b1eb0000000016f2016c#)) called at (vendor/magento/framework/Interception/Interceptor.php:138)n#29 Magento\Framework\App\FrontController\Interceptor->Magento\Framework\Interception\{closure}(&Magento\Framework\App\Request\Http#000000007de0b1eb0000000016f2016c#) called at (vendor/magento/framework/Interception/Interceptor.php:153)n#30 Magento\Framework\App\FrontController\Interceptor->___callPlugins('dispatch', array(&Magento\Framework\App\Request\Http#000000007de0b1eb0000000016f2016c#), array(array('default_store_se...', 'storeCookieValid...', 'install', 'configHash'))) called at (generated/code/Magento/Framework/App/FrontController/Interceptor.php:26)n#31 Magento\Framework\App\FrontController\Interceptor->dispatch(&Magento\Framework\App\Request\Http#000000007de0b1eb0000000016f2016c#) called at (vendor/magento/framework/App/Http.php:136)n#32 Magento\Framework\App\Http->launch() called at (generated/code/Magento/Framework/App/Http/Interceptor.php:24)n#33 Magento\Framework\App\Http\Interceptor->launch() called at (vendor/magento/framework/App/Bootstrap.php:257)n#34 Magento\Framework\App\Bootstrap->run(&Magento\Framework\App\Http\Interceptor#000000007de0b1990000000016f2016c#) called at (index.php:39)n
``````"," url ":"  / admin  / admin  / index  / index  / key  / b4625ae2ff3073ab297b349a5a752c7ca652f746f569480aaad9f498a564afcf ",", "script_name": "", "/" index.php "}
```
What could possibly be wrong?
My env

Ubuntu 18.04
magento 2.2.9
php 7.1

I have installed php by official command:
```apt-get install -y php7.1 libapache2-mod-php7.1 php7.1-common php7.1-gd php7.1-mysql php7.1-mcrypt php7.1-curl php7.1-intl php7.1-xsl php7.1-mbstring php7.1-zip php7.1-bcmath php7.1-iconv php7.1-soap
```
```

## How is it that Windows (or Linux) is apparently independent of the machine?

How can I, for example, insert a Windows installation DVD on almost any computer, have an AMD or Intel processor and still boot? How is the installation program written so that it can run on one or the other processor?

## transactions – ScriptSig does not valid with an apparently valid signature

I'm trying to build raw transactions from scratch to improve my understanding. For comparison, I use hexoutput from https://coinb.in/ because I can choose Testnet on this one.

I'm trying to build a P2PKH transaction without Segwit (for now) that should use this tx `577735da1fccf6df79eac9ff42049a7729703ec5506efeb1602bca99df3bafd2` (index 0) and send `6889990` satoshi to `mv4rnyY3Su5gjcDNzbMLKBQkBicCtHUtFB`, the raw public key of the input address is `034323ee9ac23504779b40c1b02578d27f70c12c22b7fc4f452dbbde681e45073d`

So, for the unsigned transaction, my product library `0100000001d2af3bdf99ca2b60b1fe6e50c53e7029779a0442ffc9ea79dff6cc1fda357757000000002221034323ee9ac23504779b40c1b02578d27f70c12c22b7fc4f452dbbde681e45073dffffffff0106226900000000001976a9149f9a7abd600c0caa03983a77c8c3df8e062cb2fa88ac00000000` which corresponds to what is produced by coinb.

So, to generate the signature for the script, I use the following code:

``````def sign_transaction (auto, secrets):
"" "
Sign all entries of the transaction with
a secret key.
: ECPrivKey settings[] secrets: a list of private keys corresponding to the entries
: return: Signed version of the transaction ready to be published
"" "
unsigned = bytes.fromhex (self.serialize_to_hex ())
message = sha256 (sha256 (unsigned))
copy = deepcopy (auto)
entries = self .__ entries
for i in the range (0, len (secrets)):
sk = secrets[i]
inp = entries[i]
sig = SignatureFactory.gen_ecdsa_signature_bytes (message, sk)
copy.set_signature (sig)
sigscript = sig.get_asn1_encoded () + OP_SIGHASH_ALL
l = len (bytes.fromhex (sigscript))
script = compact_size_int (l) + sigscript + inp.get_sig_script ()
copy the entries.[i].set_sig_script (script)
return a copy
``````

Informally, I use the hexoutput of the unsigned transaction, convert it into bytes, perform two sha256 hash functions on it, and add the SIGHASH ("01") byte.

I have validated the produced signature and this one is valid, so I have the impression that there is a problem with serialization. Here is my transaction after signing:

``````0100000001d2af3bdf99ca2b60b1fe6e50c53e7029779a0442ffc9ea79dff6cc1fda357757000000006a47304402207da5c1e2d7db828e415db1ae060d65e4a44de2b13b71c50be61d6c52da82425b022010da9abb70c7b6047b559c5c572f68e078d6ae78ba03dfd6aa1890e512e376760121034323ee9ac23504779b40c1b02578d27f70c12c22b7fc4f452dbbde681e45073dffffffff0106226900000000001976a9149f9a7abd600c0caa03983a77c8c3df8e062cb2fa88ac00000000

{"version": "01000000", "flag": "", "inputLen": "01", "input": [{"prevOutHash": "d2af3bdf99ca2b60b1fe6e50c53e7029779a0442ffc9ea79dff6cc1fda357757", "prevOutIx": "00000000", "sigScriptLen": "6a", "sigScript": "47304402207da5c1e2d7db828e415db1ae060d65e4a44de2b13b71c50be61d6c52da82425b022010da9abb70c7b6047b559c5c572f68e078d6ae78ba03dfd6aa1890e512e376760121034323ee9ac23504779b40c1b02578d27f70c12c22b7fc4f452dbbde681e45073d", "sequence": "ffffffff"}], "outputLen": "01", "outputs": [{"value": "0622690000000000", "pubKeyScriptLength": "19", "pubKeyScript": "76a9149f9a7abd600c0caa03983a77c8c3df8e062cb2fa88ac"}], "lock time": "00000000"}
``````

In more detail the value of sigscript:

``````47 length of the script
Signature marker 30 DER
44 length of the signature
Value Marker 02 r
20 r value length
7da5c1e2d7db828e415db1ae060d65e4a44de2b13b71c50be61d6c52da82425b r value
Value Marker 02 s
2010da9abb70c7b6047b559c5c572f68e078d6ae78ba03dfd6aa1890e512e37676 s value
01 Opcode SIGHASH
Length of 21 keys
034323ee9ac23504779b40c1b02578d27f70c12c22b7fc4f452dbbde681e45073d key key value
``````

If I try to broadcast the transaction on https://live.blockcypher.com/btc-testnet/pushtx/ I get `Error validating the transaction: error while running the script for entry 0 referring to 577735da1fccf6df79eac9ff42049a7729703ec5506efeb1602bca99df3bafd2 at 0: the script has NOT been successfully verified ..`

Does anyone have an idea of ​​what might be wrong? In addition, the value r and s of the signature I did not encode in little endian and I do not know if that could be the problem?

## summation – What is the main difference between two results of apparently similar sums?

warning

``````    Sum[(a^2 + (b + n)^2)^(-1), {n, -Infinity, Infinity}]
``````

given

$$frac { pi sinh (2 pi a)} {a ( cosh (2 pi a) – cos (2 pi b))}}$$

while the sum

``````                    Sum[(a^2 + (b + 2 [Pi] n) ^ 2) ^ (- 1), {n, -Infinity, Infinity}
``````

given

$$begin {array} {cc} {And begin {array} {cc} frac { coth left ( frac {a} {2} + frac {ib} {2} right) + coth left ( frac {a} {2} – frac {ib} {2 } right)} {4 a} & arg (b + ia) geq 0 \ frac { coth left ( frac {1} {2} (a + ib) right)} {4a} + frac { coth left ( frac {1} {2} (ai b) right)} {4 a} – frac {1} {2 a} & text {True} \ end {array} \ end {array}$$

listing two different cases. What is the source of this?

Also, ask a condition on $$a$$ to be real and positive

``````    Refine[Sum[(a^2 + (b + 2*[Pi] n) ^ 2) ^ (- 1), {n, -Infinity,
Infinite}], {Element[{a, b}, Reals], a> 0}]
``````

do not get rid of "cases", as it should be (because then the imaginary part of $$(b + ia)$$ always positive), the result remains exactly the same as above. Maybe I have not stated the assumptions on $$a$$ correctly? I use Mathematica version 11.3.0.0.

Related to
What is the meaning of True in my result?

## bitcoin – 51% attack – apparently very easy? Referring to CZ's "BTC rollback chain" – How to ensure that such a corruptible scenario can never happen so easily?

I was shocked to see binance CZ literally "canceling" the bitcoin chain by "calling" some favors of "friendly" Asian miners.

This one person could actually do it ??? I mean, are we all in a bubble, in a kind of utopia then, to think that the decentralization of the chain makes it "armored" and resistant to collusion on the part of the miners?

(1) This is a fundamental question: how do our brilliant bitcoin developers, highly respected and esteemed, explain such a situation in which only a handful of people's interests could be enough to attack with a 51% majority?

(2) Second, are there active debates on how to mitigate such a situation in the future? What technical aspects implemented in the BTC chain (or to be implemented) could be useful?

These huge mining farms are basically very disturbing. it's like a proof of stake, where the "richest" has the most power. And in the case of PoW mining, it's similar to the "biggest hardware" that has the most power.

we must try in a way to eliminate these easily corruptible scenarios, right?

In today's digital world, there are many examples of collusion involving even more than 1000 different people involved.

A handful of minor accomplices would be a piece of cake, right?

Thank you for having explained this problem. I sincerely hope that this will be picked up by our great developer community, or maybe I just do not understand anything.

## permissions – Windows 10 update 1803 has apparently revoked net stop and sc config access

Scenario:
The bandwidth on my network is rare, a batch script is bound on my desktop to end the gluttonous services, Windows Update and Broadcast Optimization being the most frequent hackers. Before the last update of Windows 10, this tool worked well, the main commands in question being

``````NET stop "Windows Update"
Net stop "Optimization of delivery"
Config SC DoSvc start = disabled
SC config wuauserv start = disabled
``````

Attempts with cmd, Services or resmon: Previously, Windows canceled all changes to the startup type, so the script was a temporary fix. Now, however, `Access is denied` for all these commands, even when the script is "Run as Administrator". Even if I run the Services utility as an administrator, all options to change the startup type or stop services are dimmed. I did not check if I could terminate these services from the Resource Monitor utility. I found that I can `take` and `of the` arbitrary executables in System32, so if anyone knows which executables for WU and DO, this can also work.

Potential solution via the registry: From this question, I discovered that it was possible to change the startup type of these services in the registry. I found that in `HKEY_LOCAL_MACHINE SYSTEM CurrentControlSet Services DoSvc` and `~ wuauserv` there is no `beginning` DWORD registry, as shown in the above question, but there are DWORD registers called `Type` in `~ % svc% TriggerInfo` for `DoSvc` and `wuauserv`. Is the edition of these `Type` Do the registers have the desired effect? If not, what would be the register?

Should I install Gentoo?

Windows 10 Home Edition v. 1803

## Is SiteDistrict worth its (apparently) high cost?

SiteDistrict is a web hosting company located in Oakland. They seem
specialize in WordPress sites.

Their price calculator on their main page uses horizontal sliders.
Examples:

– Sites: \$ 25 each for one, \$ 14 each for 10, \$ 9 each for 50, etc.
– Disk space: 17 GB included, then \$ 1 per GB per month
– Bandwidth: 83 GB included, then about 30 ¢ per GB per month

These prices seem incredibly high, but maybe I'm
missing something. Does SiteDistrict offer good value for money?
money?