How can we troubleshoot a NetBIOS/firewall issue related to MSDTC? (Funny twist included)

A friend of mine have two servers with MSDTC connecting to two SQL Servers. Everything is fine to one SQL Server, but to the other he often gets error:

Communication with the underlying transaction manager has failed. —>
System.Runtime.InteropServices.COMException: The MSDTC transaction
manager was unable to push the transaction to the destination
transaction manager due to communication problems. Possible causes
are: a firewall is present and it doesn’t have an exception for the
MSDTC process, the two machines cannot find each other by their
NetBIOS names
, or the support for network transactions is not enabled
for one of the two transaction managers. (Exception from HRESULT:

The only difference between the two SQL Servers is network (different subnet) and firewall (the one where it’s working has less restrictions). And here is the funny part, if one browse a share from the SQL to one of the two servers that is not SQL, everything works fine for a while. They suspect something with NetBIOS name resolution, but they cannot troubleshoot it in detail.

Any ideas?

windows – My PC started blue screening. How do I troubleshoot it?

Several weeks ago, my laptop started displaying the Blue Screen. First it was perhaps once a day, so I just lived with it but as of 3 days ago, it happens roughly an hour after I log in.

As you can see from the reliability app, it started on 5/12/2021.
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When I look in the details of the problem in the Reliability app for the Hardware Error entry, the problem is LiveKernelEvent, code ab.

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When I double click on “Shut down unexpectedly”, I get BlueScreen, code ca.

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The Stop Code on the Blue Screen itself is always REFERENCE_BY_POINTER.

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I googled around for these values, but didn’t get anything definitive.

So I figured some driver must have gotten installed on 5/12/2021. So I headed to Windows Update/View Update History. The last thing under Driver Updates was installed 2 months prior to blue screen issues. So it can’t be that. I also looked at other Windows Update entries and there was KB4023057: Update for Windows 10 Update Service components, but it was installed 4/29/2021, so that can’t be it either.

I then investigated Apps & Features to see if any app got installed around the time of the problem, and got some apps that, I suppose, could be suspicious.

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Finally, I went to the Dell Utility and had it run its Driver scan and it offered to install 1GB worth of updates, which I allowed. I was hopeful because it included BIOS updates. Nonetheless, the laptop still blue screened after an hour of work.

I perused the Event Viewer, but found nothing suspicious. I then ran Memtest64, which found no issues. ChkDsk didn’t either. sfc /scannow didn’t either. My next step is to upgrade from v 20H2 to 21H1 and but I am not holding out much hope for that.

What else can I do to troubleshoot the blue screens?

pp64 troubleshoot " Input error: empty matrix " Completely lost on how to troubleshoot

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This command always gives me input error when trying to pass my .txt file to pp64

coordinate transformation – How to troubleshoot TransformedField functionality in Mathematica?

I list up this method to transform a complex function to Cartestian form, which can be used on virtually any function:

such as:

u0(r_, phi_) := Sum(I^(-n) BesselJ(n, r) Exp(I n phi), {n, -5, 5});

TransformedField("Polar" -> "Cartesian",  u0(r, phi), {r, phi} -> {x, y})

which yields:

  u0(x_, y_) := 
 BesselJ(0, Sqrt(x^2 + y^2)) + 
  1/(x^2 + y^2)^(5/2)
    2 (-I x (x^2 + y^2)^2 BesselJ(1, Sqrt(x^2 + y^2)) + 
      Sqrt(x^2 + y^2) (-x^4 + y^4) BesselJ(2, Sqrt(x^2 + y^2)) + 
      I x^5 BesselJ(3, Sqrt(x^2 + y^2)) - 
      2 I x^3 y^2 BesselJ(3, Sqrt(x^2 + y^2)) - 
      3 I x y^4 BesselJ(3, Sqrt(x^2 + y^2)) + 
      x^4 Sqrt(x^2 + y^2) BesselJ(4, Sqrt(x^2 + y^2)) - 
      6 x^2 y^2 Sqrt(x^2 + y^2) BesselJ(4, Sqrt(x^2 + y^2)) + 
      y^4 Sqrt(x^2 + y^2) BesselJ(4, Sqrt(x^2 + y^2)) - 
      I x^5 BesselJ(5, Sqrt(x^2 + y^2)) + 
      10 I x^3 y^2 BesselJ(5, Sqrt(x^2 + y^2)) - 
      5 I x y^4 BesselJ(5, Sqrt(x^2 + y^2)))


a Hankel and Bessel function together:

u(r_, phi_) :=  Piecewise({{BesselJ(1.5 r, 5)*Exp(I 5 phi), 
0 < r < 1/2}, {(BesselJ(3 r, 5) + BesselY(3 r, 5))*Exp(I 5 phi), 
1/2 < r < 1}, {HankelH1(r, 5)*Exp(I 5 phi), r > 1}})

which yields:


which yields the respective given plots, when plotted:




However, my supervisor thinks these plots look “strange”.

How can I verify that the TransformedField command did the right job – for such extended functions?

In other words, how to trobleshoot TransformedField?

windows 10 – How to troubleshoot bluetooth audio for a Surface tablet?

From bluetooth settings (start ms-settings:bluetooth) clicking disconnect and connect generates an audible pairing message from the headset.

Hower, youtube or other video only seems to play over the built-in audio.

One time zoom worked.

The PLT v5200 from plantronics works with other devices.

Not sure what I can do. I removed the device and re-added it.

I removed the device from bluetooth.

Added an Alexa speaker. YouTube plays fine over the Alexa speaker.

Disconnected from the Alexa speaker.

Connected to the 5200 earpiece.
Audio still plays over the built-in speakers.

In bluetooth settings, it now shows as:

Connected voice

which is probably the problem.

seo – How can we troubleshoot why a 404 page doesn’t retain its url rather changes to another 404 page of its own?

I am working on a client website for a technical SEO audit for the first time. They have a 404 page where the URL of the missing page is not retained, instead, it goes to a separate 404 page. For example, let’s say as a user, I need to access , but this page is not there, so the browser redirects me too This page has all the content that a 404 page has, but the URL changes. Ideally, 404 page should not be there, that I understand, but for audit and temporary fix, shouldn’t the URL have been and that page should show “page not found” info? How can I check, why this is happening. Also, this page is running on a .NET platform.

Keep getting non base-58 character error when trying to recover my old wallet. Any ideas on how to troubleshoot this?

Basically I made a purchase with bitcoins back in ~2014 and I remember that I had a little bit leftover. However all documentation I have is a file labelled wallet with a huge string of characters. But when I try and access it on any application I get the non base-58 character error. There are a bunch of +’s and /’s. Does anyone have any idea what I could try to see if this is it? Sorry for not having more advance knowledge.

nginx – How do I troubleshoot 403 access forbidden by rule error?

In the first 40-50 minutes after I restart my server (Apache with Ngintron) I get a 403 nginx error, and in the logs it says “access forbidden by rule”.
I have all my traffic redirected to HTTPS.
This is my etc/nginx/common_https.conf:

# Common definitions for HTTPS content

# TLS/SSL common
ssl_session_timeout 1d;
ssl_session_cache shared:SSL:50m;
ssl_session_tickets off;

# Diffie-Hellman parameter for DHE ciphersuites (2048 bits)
ssl_dhparam /etc/ssl/certs/dhparam.pem;

# --- Protocols & Ciphers (start) ---

# Maximum client support (enabled by default)
# Supports Firefox 1, Android 2.3, Chrome 1, Edge 12, IE8 on Windows XP, Java 6, OpenSSL 0.9.8, Opera 5 & Safari 1
ssl_protocols TLSv1 TLSv1.1 TLSv1.2 TLSv1.3;
ssl_ciphers / removed /;
ssl_prefer_server_ciphers on;

# Intermediate client support (disabled by default)
# Supports Firefox 27, Android 4.4.2, Chrome 31, Edge, IE 11 on Windows 7, Java 8u31, OpenSSL 1.0.1, Opera 20 & Safari 9
#ssl_protocols TLSv1.2 TLSv1.3;
#ssl_ciphers /removed/;
#ssl_prefer_server_ciphers off;

# Modern client support (disabled by default)
# Supports Firefox 63, Android 10.0, Chrome 70, Edge 75, Java 11, OpenSSL 1.1.1, Opera 57 & Safari 12.1
#ssl_protocols TLSv1.3;
#ssl_prefer_server_ciphers off;

# --- Protocols & Ciphers (finish) ---

# Set the port for HTTPS proxying
set $PROXY_TO_PORT 443;

# Include common definitions and rules with HTTP
include common_http.conf;

Could be the problem this rule: ssl_session_cache shared:SSL:50m; ?

And this is my etc/nginx/common_http.conf:

# Common definitions for HTTP content

# Initialize important variables
set $PROXY_DOMAIN_OR_IP $host;
set $PROXY_SCHEME $scheme;
set $SITE_URI "$host$request_uri";

# Generic query string to request a page bypassing Nginx's caching entirely for both dynamic & static content
if ($query_string ~* "nocache") {

# Proxy requests to "localhost"
if ($host ~* "localhost") {
    set $PROXY_DOMAIN_OR_IP "";

# Disable caching for cPanel specific subdomains
if ($host ~* "^(webmail|cpanel|whm|webdisk|cpcalendars|cpcontacts).") {

# Fix Horde webmail forwarding
if ($host ~* "^webmail.") {

# Set custom rules like domain/IP exclusions or redirects here
include custom_rules;

location / {
    try_files $uri $uri/ u/backend;

location u/backend {
    include proxy_params_common;
    # === MICRO CACHING ===
    # Comment the following line to disable 1 second micro-caching for dynamic HTML content
    include proxy_params_dynamic;

# Enable browser cache for static content files (TTL is 1 hour)
location ~* .(?:json|xml|rss|atom)$ {
    include proxy_params_common;
    include proxy_params_static;
    expires 1h;

# Enable browser cache for CSS / JS (TTL is 30 days)
location ~* .(?:css|js)$ {
    include proxy_params_common;
    include proxy_params_static;
    expires 30d;

# Enable browser cache for images (TTL is 60 days)
location ~* .(?:ico|jpg|jpeg|gif|png|webp)$ {
    include proxy_params_common;
    include proxy_params_static;
    expires 60d;

# Enable browser cache for archives, documents & media files (TTL is 60 days)
location ~* .(?:3gp|7z|avi|bmp|bz2|csv|divx|doc|docx|eot|exe|flac|flv|gz|less|mid|midi|mka|mkv|mov|mp3|mp4|mpeg|mpg|odp|ods|odt|ogg|ogm|ogv|opus|pdf|ppt|pptx|rar|rtf|swf|tar|tbz|tgz|tiff|txz|wav|webm|wma|wmv|xls|xlsx|xz|zip)$ {
    include proxy_params_common;
    include proxy_params_static;
    expires 60d;

# Enable browser cache for fonts & fix u/font-face cross-domain restriction (TTL is 60 days)
location ~* .(eot|ttf|otf|woff|woff2|svg|svgz)$ {
    include proxy_params_common;
    include proxy_params_static;
    expires 60d;

# Prevent logging of favicon and robot request errors
location = /favicon.ico {
    include proxy_params_common;
    include proxy_params_static;
    expires 60d;
    log_not_found off;

location = /robots.txt  {
    include proxy_params_common;
    include proxy_params_static;
    expires 1d;
    log_not_found off;

# Deny access to files like .htaccess or .htpasswd
location ~ /.ht {
    deny all;

How do I troubleshoot further exactly which rule causes the issue?

How can I troubleshoot the Authorization Error?

Tested Oauth2.0 of Google Alerts via Postman but facing this issue.

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Authentication Scopes is provided as given

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Thanks for any help

Troubleshoot Sortable xProfile Column in Admin Users Screen

I’m trying to add a sortable Country column to the Users screen for one of my BuddyPress xProfile fields.
My BuddyPress field is a select2 dropdown, where my members select their country from an array of options.

I have it ~workingish~ (column is displaying on Users screen & sorting by country alphabetically) but it’s throwing a notice:

Notice: Array to string conversion in /srv/www/server/wp-admin/includes/class-wp-users-list-table.php on line 582

& 4 of my 1000+ Users are displaying Array instead of their country.

Here is the code I’ve added to a custom plugin:
(from Sortable Custom Columns in User Panel (users.php)?)

// add the custom column
function wpmeo_add_user_columns( $column ) 
     $column('Country') = 'Country';

     return $column;
add_filter( 'manage_users_columns', 'wpmeo_add_user_columns' );

// make the custom column sortable
function wpmeo_sortable_user_columns( $columns )
    $columns('Country') = 'country';

    return $columns;
add_filter( 'manage_users_sortable_columns', 'wpmeo_sortable_user_columns', 10, 3 );

// provide the custom column value
function wpmeo_user_columns( $value, $column_name, $id ) 
    if( 'Country' == $column_name ) 
        $new_column = xprofile_get_field_data( 'Country', $id );
        return $new_column;
add_action( 'manage_users_custom_column', 'wpmeo_user_columns', 10, 3 );

// sort by custom column asc & desc
function my_wpmeo_pre_user_query($user_search)
    global $wpdb, $current_screen;

    // Only filter in the admin
    if ( ! is_admin() )

    // Only filter on the users screen
    if ( ! ( isset( $current_screen ) && 'users' == $current_screen->id ) )

    $vars = $user_search->query_vars;

    if('country' == $vars('orderby'))
        $user_search->query_from .= " INNER JOIN {$wpdb->usermeta} m1 ON {$wpdb->users}.ID=m1.user_id AND (m1.meta_key='country')"; 
        $user_search->query_orderby = ' ORDER BY UPPER(m1.meta_value) '. $vars('order');

For the last function I’ve also tried:
(from Display sortable User meta column in admin panel user’s page)

// sort by custom column asc & desc
function prefix_sort_by_level( $query ) {
    if ( 'country' == $query->get( 'orderby' ) ) {
        $query->set( 'orderby', 'meta_value' );
        $query->set( 'meta_key', 'country' );
add_action( 'pre_get_users', 'prefix_sort_by_level' );

& I get the exact same notice & same 4 Users Country display is Array. There is nothing special about these Users or the countries they have selected. I’m assuming that the issue is the type of field (select2 dropdown) but I don’t know how to modify either function accordingly.