I was able to make ThingWorx works with SQL Server as Persistence Provider.
I have attached my simple platform-settings.json file for reference.
I would think the current error is because you are missing the element PersistenceProviderPackageConfigs in your json
After that it worked all right
Hope this helps
platform-settings.json.zip 375 bytes
Christophe and Polina,
Thank you both for taking the time to respond. I apologize for not replying sooner. The 7.4 installation with SQL Server was very challenging for me and there were so many possibly root failure points to work through, inconsistent sample platform-settings.json, similar sounding but unrelated failure modes etc. It was very frustrating. In the end I bit the bullet and dropped the SQL Server database and reran the database and schema installation scripts and finally the server started up like a charm. The issue was not in my platform-settings.json after all. I was thrown off the scent I think because the initial installation had resulted in a number of tables being created in the database. As soon as I ran it the second time I noticed right away there were many more tables than the first time and so it appeared that the script had failed mid way through for some reason.
I had seen mentions elsewhere to re-install the database in case of issues but I was too stubborn to go there. Thanks to Polina for pointing out the fact that there is JIRA ticket pertaining to intermittent script failures. That was the nudge in the right direction that I needed.
Thank you both again and for anyone else having trouble installing with SQL Server, don't hesitate to clean the database and rerun the installation scripts. I'm very happy now because the restart times for my 7.2 / H2 instance was on the order of 6 minutes and now with SQL Server that's down to 45 seconds.