Can you post ok without the menu link widget? If so try to upload and install a new version of the widget, it may just be a widget error.

However what are you using the widget for? I have it twice in my menu, once for a pre-defined contact and another for a pre-defined login not for a url specified by me

Probably a good idea to change the title, if you can, to be more descriptive with (menu link widget)

If the error is for the contact page it looks like it can't find it
Call to a member function get_contact_url()

Looking at the code in the widget
if( ! $url = $current_Blog->get_contact_url( true ) )
{ // user does not allow contact form:

it seems you also have to have the contact from enabled but I don't think this would cause the errror ?? still could be it can't find the form

Thanks for that. I suspected it couldn't find the contact page, and I found after a while that it was because I had not correctly identified the blog in the appropriate blog index page. Wrong number! Seems odd because I had earlier been working through entries with no problems. Any, seems to be OK.

Correct configuration would surely go a long way.

@tgodfrey we'd still love to be able to fix this but we cannot reproduce the bug even with a wrong collection ID.

Can you still reproduce this bug in version 6.6.0 ?

@tgodfrey If the problem persists, this change should fix it:

https://github.com/b2evolution/b2evolution/commit/91188a47eaa1c499ed835930516abb05b709a4e7#diff-274c3d158de3dcd249dbe576ceaf0cc2