Error is generate by MainClass:
ReflectionException Object
(
    [message:protected] => Trying to invoke protected method userModule::signup() from scope ReflectionMethod
    [string:Exception:private] => 
    [code:protected] => 0
    [file:protected] => /var/www/vhosts/alfalab.md/httpdocs/main/classes/Abstract/genericApplication.class.php
    [line:protected] => 98
    [trace:Exception:private] => Array
        (
            [0] => Array
                (
                    [file] => /var/www/vhosts/alfalab.md/httpdocs/main/classes/Abstract/genericApplication.class.php
                    [line] => 98
                    [function] => invoke
                    [class] => ReflectionMethod
                    [type] => ->
                )

            [1] => Array
                (
                    [file] => /var/www/vhosts/alfalab.md/httpdocs/appl/application.class.php
                    [line] => 331
                    [function] => callFuncFromModule
                    [class] => genericApplication
                    [type] => ->
                )

            [2] => Array
                (
                    [file] => /var/www/vhosts/alfalab.md/httpdocs/appl/application.class.php
                    [line] => 260
                    [function] => isspecialurl
                    [class] => application
                    [type] => ->
                )

            [3] => Array
                (
                    [file] => /var/www/vhosts/alfalab.md/httpdocs/appl/application.class.php
                    [line] => 54
                    [function] => getrequestcontent
                    [class] => application
                    [type] => ->
                )

            [4] => Array
                (
                    [file] => /var/www/vhosts/alfalab.md/httpdocs/main/mainClass.class.php
                    [line] => 270
                    [function] => processModuleRequest
                    [class] => application
                    [type] => ->
                )

            [5] => Array
                (
                    [file] => /var/www/vhosts/alfalab.md/httpdocs/main/mainClass.class.php
                    [line] => 258
                    [function] => processRequest
                    [class] => mainClass
                    [type] => ->
                )

            [6] => Array
                (
                    [file] => /var/www/vhosts/alfalab.md/httpdocs/index.php
                    [line] => 20
                    [function] => processSiteRequest
                    [class] => mainClass
                    [type] => ->
                )

        )

    [previous:Exception:private] => 
)