Hello,

I'm trying to solve this issue for several days now. Seems like this is a rare Firefox bug with internal database that occurs for some users usually with very old Firefox profile. So far only solution I could find is create new Firefox profile. But don't loose hope, I'm still trying to find a proper solution or better work-around.
I'll let you know once I know more.

I'm really sorry for the inconveniences.

Have a nice day!

Best regards,

Juraj Mäsiar