I just upgraded to 4.2.1946 and encountered this for the first time on my phone, when clicking "Newest".
Error
Access denied to file C:\Documents and Settings\elevenchars\My Documents
That's the only interface element that gives an error. I've made no changes other than the upgrade.
It's not clear from the message whether the path is truncated or not, but I'm going to intuit that it is indeed truncated -- to 50 characters exactly. So the error message doesn't tell me what I need to know to resolve the issue on my own.
The server logs tell no story at all. I have no trailing slashes in any paths.
Service is running as local system.
Any ideas?