We still have Microsoft SQLServer 2012. The driver included with Tableau up to 10.5 supported this database just fine.
I just updated to 2018.1 and I can no longer access our SQLServer 2012. Based on the error message, it looks like a new driver was installed that does not support SQLServer 2012.
Is there any way to downgrade the driver? Or is there some other solution?
SQL Server drivers are almost always backwards and forwards compatible, so my guess is that something else is going on here. What is the error you are receiving?