Error in Auth page

Hi Guys,
After the last update i have an error in the Facebook authentication page.
After i follow the process (that worked perfectly till now), it goes to a generic wordpress error page without giving us a proper explaination of the error and doesn’t get the token.
I’ve already tried to remove the app in the Fb Business page and reconnect with no luck, and then i’ve uninstalled and reinstalled your plugin and done everyhting from a fresh start with no luck.

The feed disappeared from my website and there’s no way to have it back. We also tried with another Fb account and nothing change.

Any way to fix this?
Best.
Antonio