netscape.security.PrivilegeManager is coming undefined in mozilla firefox but in internet explorer or chrome its working fine.i am using 60.6.1 esr version. can you please give me any solution.i also tried to remove extension but that solution not working for me. 

duplicate of [/questions/1258807] thread. Hi, netscape.security.PrivilegeManager is coming undefined in mozilla firefox but in internet explorer or chrome its working fine.i am using 60.6.1 esr version. can you please give me any solution.i also tried to remove extension but that solution not working for me. Thanks