Some web pages did not load correctly. (on Imac). Deleted Firefox and moved Profile to another drive to backup. Downloaded new Firefox. When I try to install, I keep getting this message-"A copy of Firefox is already open. Only one copy of Firefox can be open at a time." I went in and searched for all occurrences of Firefox or Mozilla and deleted. It will still not load. I cannot get Firefox to run now. I backed up my Profile to another drive. Cannot create a new one as Firefox will not run. It says there is another copy running. However, I have deleted all Firefox and Mozilla files and downloaded new. When I try to run it, I get the message to close Firefox as two cannot run at once. I did create a new Mac account logon and can run Firefox there, so something in the other account is showing Firefox is running. I also checked in ACTIVITY MONITOR and in SETUP and there is no Firefox or Mozilla running. So, where can this bug be hiding????