remains api – error Magento 2 swagger-ui

I'm trying this url http://192.168.1.67/isac/swagger but I had this error below

    500: {"message": "Internal error." Details are available in the Magento log file.
Report ID: webapi-5bfe5e3ac4100 "} http://192.168.1.67/isac/rest/default/schema?services=all

When I checked the exception log file, I got the information below.

[2018-11-28 09:24:07]    main.CRITICAL: LogicException: The class "array" does not exist. Please note that this namespace must be specified. in /var/www/html/isac/vendor/magento/framework/Reflection/TypeProcessor.php:156
Trace of the pile:
# 0 /var/www/html/isac/vendor/magento/module-webapi/Model/Config/ClassReflector.php(103): Magento  Framework  Reflection  TypeProcessor-> register (& # 39; array & # 39;)
# 1 /var/www/html/isac/vendor/magento/module-webapi/Model/Config/ClassReflector.php(72): Magento  Webapi  Model  Config  ClassReflector-> extractMethodData (Object (Zend  Code  Reflection )  MethodReflection))
# 2 /var/www/html/isac/vendor/magento/module-webapi/Model/ServiceMetadata.php(119): Magento  Webapi  Template  Config  ClassReflector-> reflectClassMethods (Al Altius  Customap. .. #, Table)
# 3 /var/www/html/isac/vendor/magento/module-webapi/Model/ServiceMetadata.php(148): Magento  Webapi  Model  ServiceMetadata-> initServicesMetadata ()
# 4 /var/www/html/isac/vendor/magento/module-webapi/Model/Rest/Swagger/Generator.php(913): Magento  Webapi  Model  ServiceMetadata-> getServicesConfig ()
# 5 /var/www/html/isac/vendor/magento/module-webapi/Controller/Rest.php(278): Magento  Webapi  Template  Rest  Swagger  Generator-> getListOfServices ()
# 6 /var/www/html/isac/vendor/magento/module-webapi/Controller/Rest.php(214): Magento  Webapi  Controller  Rest-> processSchemaRequest ()
# 7 /var/www/html/isac/vendor/magento/framework/Interception/Interceptor.php(146): Magento  Webapi  Controller  Rest-> dispatch (Object (Magento  Framework  App  Request  Request  Http ))
# 8 /var/www/html/isac/var/generation/Magento/Webapi/Controller/Rest/Interceptor.php(39): Magento  Webapi  Controller  Rest  Interceptor -> ___ callPlugins (& # 39; dispatch & # Array, Array)
# 9 /var/www/html/isac/vendor/magento/framework/App/Http.php(135): Magento  Webapi  Controller  Rest  Interceptor> dispatch (Object (Magento  Framework  App  Request  Http) ))
# 10 /var/www/html/isac/vendor/magento/framework/App/Bootstrap.php(258): Magento  Framework  App  Http-> launch ()
# 11 /var/www/html/isac/index.php(40): Magento  Framework  App  Bootstrap-> run (Object (Magento  Framework  App  Http))
# 12 {main}

Next exception: Report ID: webapi-5bfe5eb799b72; Message: The class "table" does not exist. Please note that this namespace must be specified. in /var/www/html/isac/vendor/magento/framework/Webapi/ErrorProcessor.php:195
Trace of the pile:
# 0 /var/www/html/isac/vendor/magento/framework/Webapi/ErrorProcessor.php(139): Magento  Framework  Webapi  ErrorProcessor -> _ critical (Object (LogicException))
# 1 /var/www/html/isac/vendor/magento/module-webapi/Controller/Rest.php(219): Magento  Framework  Webapi  ErrorProcessor-> maskException (Object (LogicException))
# 2 /var/www/html/isac/vendor/magento/framework/Interception/Interceptor.php(146): Magento  Webapi  Controller  Rest-> dispatch (Object (Magento  Framework  App  Request  Request  Http ))
# 3 /var/www/html/isac/var/generation/Magento/Webapi/Controller/Rest/Interceptor.php(39): Magento  Webapi  Controller  Rest  Interceptor -> ___ callPlugins (& # 39; dispatch & # Array, Array)
# 4 /var/www/html/isac/vendor/magento/framework/App/Http.php(135): Magento  Webapi  Controller  Rest  Interceptor> dispatch (Object (Magento  Framework  App  Request  Http) ))
# 5 /var/www/html/isac/vendor/magento/framework/App/Bootstrap.php(258): Magento  Framework  App  Http-> launch ()
# 6 /var/www/html/isac/index.php(40): Magento  Framework  App  Bootstrap-> run (Object (Magento  Framework  App  Http))
# 7 {main} [] []

It's very confusing and like the most difficult puzzle game. How to solve this problem and get a swagger api?