See this statement from the PA State Police:

Outages of PICS are common, and far more prevalent than the federal system. This is several days that the people of Pennsylvania will essentially be denied their Second Amendment rights. The State Police has shown they are unable to run a reliable system, that’s respectful to the Constitution rights of its citizens. I think it’s time to end PICS, and switch to using the federal NICS system, which is doesn’t have severe reliability issues.