If you had the QTCORE4 error before you installed the Lumix software then no it's not related. Download and install
CCleaner and then open it up and choose the second tab on the left: "Registry". Then tell it to scan for issues, select "fix the issues", create a backup (just in case), then "fix all selected issues". That will likely get rid of your QTCORE4.DLL boot error.
Your other issue may be be a software programming problem. I would contact Panasonic support or check if they have a forum? Or look for a software update ... is there a version 9.2 ? or maybe try an older version?