I had this problem recently - I bought Sonar X2 Producer decades ago, and used CbB.
Recently I've given the new Sonar a go- Seemed fine until they updated all my Sonitus inserts to Sonar Core inserts irreversibly- Core inserts require Bandlab membership which is not free, so be aware that activating Sonar will change your inserts and music without asking.
Bit disappointed that Bandlab/ Cakewalk felt the need to hold my paid for inserts (On Sonar X2, when it was Roland) to ransom to try and get my membership.
Working on a workaround now.
CbB won't even open, since the updates.
And the suggested fix in the opening post just leads to multiple crashes, when attempting to open recent projects.