Odd Database Issues with WooCommerce and Other Plugins

[Michael Cropper]

This one is baffling me.... all of a sudden on one specific website when trying to upgrade WooCommerce is failing to update because 4x database tables don't exist, the actionhandler_ tables - when trying to update from WooCommerce 3.9.2 to 4.2.0. 

Usual debugging steps... disabled all plugins, removed all custom code (didn't change theme back to default), yet even will all plugins except WooCommerce disabled, the errors were still showing. So I then reverted back to WooCommerce 3.9.2 to try to upgrade again to see if these are 4 new tables that are required with this latest version - still the same issue with saying the tables don't exist. 

What is odd if that the core theme/plugins on this site are very similar to others hosted on the same server, and those other websites all work. 

So I copied the schema for the 4x missing tables from a working site over to the broken site to see if this solved the issue, but then more tables were being flagged as not existing, wc_ type tables. 

My feeling at the minute is that someone who has access to the site (it's not my site) has run some form of database cleaning plugin that has incorrectly identified database tables as being not required and it has deleted them and messed things up, but no way to prove either way on that other than the fact that the tables aren't in the database any more. 

What would you recommend here? Is there a handy plugin that can review the database schema to identify missing tables and create them again if they don't exist?

The site is back up and running after all the testing and is still on WooCommerce 3.9.2 - so the next step is to extract all the customer/order information, put a pause on anything new being ordered, completely uninstall and then re-install WooCommerce which should delete the tables then re-create them all again. Not ideal having to do this, but seems to be the only way to get these things working again. 

What is also odd, not sure if it is related, but a couple of other plugins are also reporting that they cannot create database tables. Which is odd since the database user configured in wp-config.php has full access to do what it needs, so seems odd that this behaviour is also having issues with other plugins. I'm wondering here if as part of the various migrations this database has had over the years that there are some odd configurations / setups at the database layer that is causing issues with the latest version of WordPress. All very odd since no other sites on the server are having these issues. 

Thoughts?

Regards,

Michael