Edit Post and Pages goes Blank

We have set up Ultimate Member on a site.

But when we´re facing some trouble, the edit post and pages are blank, if we deactivate the plugin this pages work normally. Also we´re getting a lot of Error 500 when the plugin is activated.

In a fresh install the plugins works fine, the problem is, is a really really big site, so we cant rebuilt again, any thoughts?

Just tried to create a new ticket on the website, but couldn´t find the button

https://wordpress.org/plugins/ultimate-member/