Howard Miller

Well, you've come to the Moodle forums, asking if Moodle is any good. I think the answer might be predictable.

It can do all those things with the possible exception of "Invoicing that can sync with FattureInCloud" because I don't know what that is. Moodle Moodle is NOT an eCommerce solution. The payment modules are fairly simplistic. If you need something more exciting, Moodle can be paired with Wordpress to get around that.

It would help to see ALL of that error trace. The interesting bit is probably after the ellipses

Sounds very similar to my use...

I'm not really answering your question, but... as Moodle doesn't use transactions, it's not immune to things like race conditions in the database. If your site is big enough and/or old enough, you'll get some low-level database corruption eventually. Probably what's happening here. Hopefully, it's a one-off and the query to detect this has done its job.