Did you try turning off Realtime Error Checking?

Are you able to share the project? If so, please PM me. I'd be interested to see if I can repro here...

We have a fix in the next update, but in the meantime keeping the globals window closed when you’re not using it should work around the issue. Let me know if this doesn’t work in your case!

Did some digging and it seems like there is an upper limit on the number of menu items you can add to a menu in Unity. After that, you get an error each time you try to add an item. It's these errors that cause the freeze.

In the next update, I'll either cap the menu items or just popup "Select GameObject" if the menu is too long.

In the longer term, we'll be replacing most menus in Playmaker with searchable popups like the Unity component menu.

Looking into the other issue you mentioned...

I’ll look into this. Very long freezes can be caused by error spam. Console logging in Unity is very slow, so if you have thousands of message it can freeze the editor for a while. The error message in the original post is strange, haven’t seen it before, but I’ll investigate what might be causing that... Are there more details in any of the error messages? E.g., a stack trace with filenames and line numbers?

Looks great! Would love to see more gameplay footage...

Looks amazing!

Can you share your project? If so, please PM a Download link and I'll take a look.
Also, can you post the full error?

And please confirm the full version info for Unity and PlayMaker from the About windows.

Thanks!

Does it happen in a new project?