Not sure if the cause is the same, but I’ve seen quite a few issues when people upgrade to the latest version of Grav. And “latest” is a bit fluid, since a “latest” seem to arrive almost every day.
Just to let you know, here’s today’s note from Andy (the lead developer):
FYI, i’ve removed ALL the 1.7.50.x releases until I can get a handle on the safe-upgrade issues that we’ve been having. This was intended to be a better upgrade system for Grav, but it’s actually been a nightmare, and is causing more issues than it solves. The next version will be a 1.7.51 release with these issues sorted
Thank you, the updates went smoothly. The only thing I haven’t tested yet is the Russian language setting in the admin panel; previously, selecting Russian would cause the system to crash.