I created a test search, then I tried to add a widget of it into the footer, however the widgets are not working at all. I disabled ajax search pro to see if this plugin is causing the issue, but it’s not, the error is still there. It is not possible to create any widgets. I see the following error on the firefox console:
NetworkError: 500 Internal Server Error – http://dev.mlatc.org/wp-admin/widgets.php
This usually indicates conflicts within plugins, or the .htaccess file or with file permissions.
Try to disable all plugins and see if you can create widgets. If not, then try to enable them one by one and perhaps you will be able to determine which one is causing the issue.
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