Please upgrade to 2.3 here.
The 2.2 and earlier branches are no longer being updated.
Patch for ProxyConnect problems
Here is the solution to the problems with ProxyConnect 1.8.4:
The bug causes the first 4 characters of the SSO response to be discarded. If your SSO response starts at the exact beginning of the http body, you'll have a problem.
(Note this is part of Vanilla core, the ProxyConnect plugin uses it.)
Around line Line 1250 of Vanilla release 2.0.14
The reason this bug didn't affect everybody:
If your SSO response started later on in the http body, then the omission of the first 4 characters wouldn't affect you.
My thanks to the Vanilla sw developers for some great sw! I've just started using it and am very pleased with it.