in qsys ALTPLL component aborts at starting.the component flashes in to qsys and then disappears.I used it properly till yesterday.all of a sudden, ALT PLL is not opening in qsys. i tried re installing quartus subscription package.still it remains the same.
There may be a problem with your project. Try creating a new blank project and see if you can use the ALTPLL component. If you can, you might try re-creating your project. It might also be caused by files in one of the .quartus directories in your home folder. I'm not sure how to fix these.
You should make a service call to Altera for help with this. There are some other things you might try but I hesitate to recommend them because they might break your installation.