412 Precondition Failed



After logged in the admin section of my grav sites, I’ve all the time the 412 Precondition Failed errror (a red box each time that I select an option, page or anything) that says:

412 Precondition Failed

Precondition Failed

The precondition on the requests for the url

/admin/notifications.json/task:processNotifications evaluated to false

Additionally a 412 Precondition failed event was encountered while trying to use an Error Document to … and can’t read anymore because do not fit in the screen.

Any help will be appreciated.