Can't add or edit posts

After installing the qtx plugin I can’t add new posts or edit posts The rest of my site works as normal. I uninstalled the plugin, used WPML to remove some of the changes the qtx plugin did to my database, but it seems there are still some issues left.

I have unactivated all other plugins to check if some of these could cause the issue, tried different computers and emptied cookies and cache in browser, without success.

I suspect the issue could still be caused by changes to my database that came when installing qtx

Could someone please help me out in order to fix this issue?

https://ww.wp.xz.cn/plugins/qtranslate-x/