No files on installing launcher

So i decided to change my mine-craft name today, it changed but the launcher wont verify the username so i reinstalled it but upon reinstalling i could not open it anymore and when i opened file location there was nothing the file in .mine-craft was still the log file there but not in the main game folder.

i searched on google and found a similar problem in bug report MCL-11754 but couldn't find a proper solution in there can you guys please help me?

It usually shows updating native launcher but gave a launcher.dll not found error