Hi,
Yes, over the last week I have also had the same issue with the exact error as yourself.
Have been tried to research the problem, but have not found any exactly to understand what the problem or fix is.
I cleared the cache, deactivated the W3 Total Cache plugin.
Waited for some time, and then activated it.
No errors for several hours and then it started again.
I also have a plugin that started have errors because of something with W3 Cache. The author of that plugin said that it was something to do with W3 Cache doing excessive caching.
So went to PHPmyAdmin and repaired the table that the other plugin error was showing, i.e. terms.
Things stay okay for several hours.
But continue have the same problem.
So if you find something to fix this… please let know.
Thanks.