Problem with "ANOTHER TAB IS ALREADY WORKING ON THIS".

Hi there

Huston, we have a problem. Page dont load to 100% - it is stuck on 48% when loading Upfront. (with "...another tab" in background)
I have done everything i could find. Deleted cache, used another web-browser.
Even loaded a backup from yesterday... no luck... still stuck... even a three day old backup would not help.
It seems like the problem arrived after last WPMUDEV updates. When i start working with google maps (in upfront), the page went into small "hicups", if i can use that word. I had to shut down and load a new session.... ups... Now i cant enter the site anymore.

Need guiding here.

Best regards
Eivind R