[TYPO3-english] Invalid request for route /main

[Éric Thibault]

Salutations!

Since 2 days, we are not able to login in our latest Typo3 site (in place since last month) version 7.6.9.  We have a message saying that the request route to main is invalid:

Invalid request for route "/main" | TYPO3\CMS\Backend\Routing\Exception\RouteNotFoundException thrown

I am able to login in the install tool and empty the caches and clean the temp repository but nothing works!

I've found this issue https://forge.typo3.org/issues/69763 and changed IP mask to no avail!

But I've tested with an other never used navigator and... it worked! Now I've cleaned all history from my regular browser and I can login now.

Is this a browser issue and/or a Typo3 issue? My clients are completely lost!  I keep testing and searching for an explication and a robust solution.

Can anyone shed light on my case?

Thankyou a million times!



Eric Thibault