UsersWP corrupts permalinks upon activation

I have confirmed that activating UsersWP causes permalink corruption on my site.
After 4 times in a row of the same result.
After I activate UsersWP I begin getting PHP errors across the top of my screen that start like this:
Warning: preg_match(): Compilation failed: nothing to repeat … [yoursite]/wp-includes/classes.php on line 222

The last error is Warning: Cannot modify header information – headers already sent by (output started at [yoursite]/wp-includes/classes.php:210) in [yoursite]/wp-includes/pluggable.php on line XXX

After this, the only solution is to deactivate ALL plugins,
change the permalinks structure back to default,
check the page to see if the problem is solved,
change permalink structure back to the custom one used,
(in my case [your site]/%post_id%/%postname%/ )
Then check page again to see if fix still works,
re-activate all plugins EXCEPT UsersWP!
check again to see if fix still works.

At this point, as soon as I re-enable UsersWP, the permalinks are corrupted somehow. Also, please note that rebuilding the permalink structure with Permalink Manager Lite does NOT fix the problem. The above procedure is the only thing that fixed it for me and is the recommended solution from the Google search results hive mind.

I really wanted to use this plugin, but if it’s going to cause these issues each time I guess I’ll have to pass.