I have SSMS 2018 installed on Win10 and it keeps on refusing to start. I click the icon, I hear a windows audible error but no error message shows. I had the same issue before so I uninstalled and reinstalled SSMS. The problem is resolved for maybe a day (or possibly a few restarts) but then reappears. I had enterprise and developer edition of SQL server installed so uninstalled enterprise as do not need it.
I stumbled across one nugget of information. If I do a net start mssqlserver from the cmd prompt I see "system error 5 has occurred Access is denied."
All the MSSQL services seem to log on as Local System - I had read that the wrong user here could cause the issue