Activating Customized Plugins on Elgg 3.0 Error

I have my website running on Elgg 2.7 and wanted to try out Elgg 3.0. After installing everything, Elgg 3.0 worked fine on browsers. Then i rsync my customized plugins with Elgg.3.0 plugins and it still worked. But when I tried to activate my own plugins, I got 'Cannot register languages....' error. So i fixed this problem by using 'return array(.....)' instead of assigning an array to a variable and using 'add_translation('en', $my_var) in my_plugin/languages/myfile.php. My real problem starts here:  i loaded my website, my plugin that I previously activated and had the error was not listed in my https://mysite.com/admin/plugins. So I renamed that plugin, reloaded the page, and that plugin was there. Then I renamed it back to the original name, it still does not show in my plugins list. Any ideas what I have done wrong or suggestions to fix my issue? Thank you very much!