I see a lot of related questions, but none that quite handle the following:
System: Ubuntu/Wordpress 4.9.8 Civi 4.7.23
I'm about to upgrade Civi but the error about "Timestamp mismatch" is making me worry.
The MySQL time stamp is correct and matches "date" on the server.
The Wordpress time setting is correct and matches "date" on the server.
The PHP time setting as exposed in phpinfo() is correct although it of course doesn't spell out a time, just a timezone, which is correct.
So why is this error persisting?