The OS that you were using? Try the following:
1) install currprocess https://www.nirsoft.net/utils/cprocess.html and disable all the software running behind there
2) disable the anti virus
3) close all the Quartus software
go to c:/user/<username>/ rename the quartus2.ini and quartus2.req for windows
cd to home/<user>/.altera.quartus rename the quartus2.ini and quartus2.req for linux
and reopen the quartus. this will reset the initial setting of the quartus prime.