Hi, I wonder if anyone has come across this particular issue when upgrading. I follow both the version specific and general upgrade guides regarding the upgrade. copy and overwrite the existing bin, Umbraco and Umbraco_Client folders, merge the webconfig files from old to new, making sure that no existing code is overwritten.

Finally merge the Dashboard and Trees /config files. The front end is fine, so get no problems with any subpages etc. However when I try to login to the backend I just get a blank screen. The login page appears, but passing the credentials to it and nothing.

I've done several version upgrades before and this is the first time I've seen this behavior. Has anyone any suggestions?

Many thanks.