I realize this is an oldish thread, but you may find like I did that TC2018 stops working after installing TC2019. I called tech support and got the advice about deleting dbautosrvwrapper.exe and TCWelcomeSplashTest.exe. I did that for both TC2018 and TC2019 and it worked, for a short while. I discovered that at some point while using TC2018 it will reinstall dbautosrvwrapper.exe FOR TC2019! After that you can't start TC2018 again because it has now linked to that file somehow. While using TC2018 you will actually get a pop up asking if it's OK for TurboCAD to make changes to your system. Sometimes it shows the .msi install file name.
To get around this annoying persistence, I modified the desktop shortcut so it runs this command (as Administrator) instead of launching TC2018 directly. You can do the same for TC2019, of course.
C:\Windows\System32\cmd.exe /c del "C:\Program Files\IMSIDesign\TCW2019\Program64\dbautosrvwrapper.exe" & "C:\Program Files\IMSIDesign\TCW2018\Program64\tcw25.exe"
It's not perfect, but was the easiest workaround I could think of right off. It attempts to delete the problem file then starts TurboCAD. One quirk is it opens a CMD window, but you can set the shortcut to run that window Minimized. (If the file hasn't been reinstalled, there will be file not found error in the window, but just ignore it.) Don't try to close that window, it'll go away once you exit TurboCAD.
It doesn't fix the annoyance of TC2018 stopping at some random point while you're working to reinstall dbautosrvwrapper.exe, but that should happen only once per session.