BuddyPress.org

This first step is to deactivate all other plugins apart from BuddyPress and see if that fixes it, second step would be to try a default these such as 2017.

There’s a few debug tools you can use but none of them is guaranteed to find the error, als they are likely to show up a bunch of errors you are not aware of.

First thing to do is turn on WP’s debugging, but it’s not recommended for highly active sites as it can cause performance issues. But if you want to try it you can put these lines in your wp-config.php:

define('WP_DEBUG', true);
define('WP_DEBUG_LOG', true);
define( 'WP_DEBUG_DISPLAY', false );

Then you can try loading Query Monitor, this will add a highly detailed view of wht’s going on in your site, it will also highlight any errors it detects. Debug Bar is another one, though that’s really for JavaScript errors.

There probably is, but I’d not recommend going down that route, especially on a live site. There’s an error, trying to force it to work like that is likely to create more errors.