hmm, sounds like I got the exact same issue:
Membercheck keeps returning
"The group NewsEditors could not be found..."
while it does exist. I copy-pasted the name from group in the snippet call and tried to create a group based on the name in the error message(group with that name already exists) so I’m pretty dam sure I typed it correctly.
I’m using 1.2-beta2 so perhaps that’s why I can’t retrieve the piece of code you mentioned.
That or I’m just not sure what you mean by
Try changing the test in the snippet to:
if ($modx->user->isMember('groupname')) {
}