There is a hidden folder called ProgramData. You have to tell Windows to “show hidden folders/files”. Inside is a DAZ 3D folder and inside of that is the content management services folder with the databases folder inside.
I really can’t advise if you only erase one of those files inside or the whole folder. I erased the whole database folder. Uninstalled DAZ Studio 4.5 and Content Management Service. Then reinstalled everything. But I may have gone overboard. At least that is what I remember. I haven’t had a CMS crash since discovering what was causing the issue.