Hi
Have come across similar problems earlier, when launching the SQL Developer for the first time on a machine
The solutions provided in the forums have many a times invlolved making changes to the config files, as a kind of hack - I try & avoid these
So this time when I got it with sqldeveloper-21.4.0.346.2239-x64 on a Windows Server 2008 R2 SP1 machine, I gave my research a little more time
Finally, I just installed the Visual C++ 2015 Redistributable (x64) 14.0.23026 and SQL Developer was able to start up fine
Wanted this to go on record for the benefit of all
Thank you :-)