>>For a while, I get blank page (URL https://www.levelextreme.com/ViewPageGenericWorker.aspx) after the first login in Firefox. Subsequent login works.
>
>ACK
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>But this is true since a lower number of hours, it worked for me 6 hours ago.

I have no idea what you are saying.
Keep in mind, that I'm not opening UT on new tab but it's open already on a tab that Firefox remembers from previous session.