Hi, You can try to start Firefox in [https://support.mozilla.com/en-US/kb/Safe%20Mode Safe Mode]. You can then try to '''Disable''' suspicious downloader/video '''Extensions''' in '''Tools''' ('''Alt '''+ '''T''') > '''Add-ons'''. Alternatively you can also try the [https://support.mozilla.org/en-US/kb/reset-firefox-easily-fix-most-problems Reset Firefox] feature via '''Help''' ('''Alt''' + '''H''') > '''Troubleshooting Information'''. (To revert to the previous profile you were using, close the new profile (i.e. exit Firefox), start Firefox and choose the '''Default User''' profile. While the [https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles Profile Manager] is open, you can also delete the newly reset profile (the one containing random numbers), or the former profile, as the case may be). If the reset is okay, it would be a good idea to delete the old profile as otherwise it would be left intact with the previous data/cache until deleted. [https://support.mozilla.org/en-US/kb/Managing-profiles Managing profiles] [https://support.mozilla.org/en-US/kb/Profiles?s=profile&r=2&e=sph&as=s Profiles Howto] [https://crash-stats.mozilla.com/report/index/090a7561-f82d-47cc-b9ea-473702120821 Crash Report] [https://support.mozilla.org/en-US/kb/helping-crashes Crash]

Looks like a problem with Browser Manager ([@ browsemngr.dll@0x11a7e3]). Try: *[[/questions/934390]] *http://systemexplorer.net/file-database/file/browsemngr-dll

As was pointed out, Babylon toolbar and Babylon search had been installed on my computer. I could not start Firefox even in safe-mode, eventually I re-install Firefox and the problem is resolved. Thanks!