Error when subscribing to a topic

[MegaVolt]

Good afternoon.
Recently, I regularly encounter one error. It appeared about a month ago (approximately). If I click the notify button I see an error: "Session verification failed. Please try logging out and back in again, and then try again."
Sometimes it is treated by reloading the page. Sometimes I need to clear cookies and log in again. But nothing helps now It happens with the theme: https://www.eevblog.com/forum/testgear/rigols-new-dho800-oscilloscope-unbox-teardown/

At the same time, I can quite easily subscribe to another topic, which means that everything is in order with the session.

[Kean]

Also being discussed in another thread
https://www.eevblog.com/forum/news/session-verification-failed/