I was getting Userenv errors on client Windows Event Viewers and after following TID 7002696 I found this extension was the cause of the errors:

[{42B5FAAE-6536-11D2-AE5A-0000F87571E3}{40B66650-4972-11D1-A7CA-0000F87571E3}]

I had to remove it from both User and Machine extensions.

The only info I could find on google is that this is related to a login/logout script. Does anyone else know additional information or have experience with this specific extension?