Firefox opens as clear window in W7 64bit; same in safe-mode - how do I fix that?
W7 64bit Firefox suddenly started opening as a clear window, only a red cross top right hand corner. Tried re-downloadiing and reinstalling and same issue. Tried running in safe mode Have restarted computer Can run Google Chrome (don't want to use IE so quickly got chrome) without any issues and have not changed anything on the computer before it stopped working or after. Last windows updates were over a week ago and firefox was working fine after that. I have just recently done a AV scan with threats removed but again Firefox was working after that and after many shutdown/restarts after that. A week prior to this issue I edited start up via MSCONFIG to stop some unwanted programs running at startup - again, many restarts and shutdowns since then with Firefox working successfully each day.
Chosen solution
A possible cause is security software (firewall,anti-virus) that blocks or restricts Firefox or the plugin-container process without informing you, possibly after detecting changes (update) to the Firefox program.
Remove all rules for Firefox and the plugin-container from the permissions list in the firewall and let your firewall ask again for permission to get full unrestricted access to internet for Firefox and the plugin-container process and the updater process.
See:
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Chosen Solution
A possible cause is security software (firewall,anti-virus) that blocks or restricts Firefox or the plugin-container process without informing you, possibly after detecting changes (update) to the Firefox program.
Remove all rules for Firefox and the plugin-container from the permissions list in the firewall and let your firewall ask again for permission to get full unrestricted access to internet for Firefox and the plugin-container process and the updater process.
See:
from another user we found out that this might be related to malware active on your pc. please close all firefox windows and try running firefox in safemode (by pressing the shift key while you're starting it). in firefox safemode go to firefox > addons > extensions and remove the entry named "Codec v1.0" or any other addons that look suspicious & you have not installed intentionally. afterwards see if you can run firefox normally again...
please also do an in-depth scan of your system with the security software already in place and/or a different tool like the free version of malwarebytes & keep firefox and your plugins up-to-date in order to stay safe on the web.
Troubleshoot Firefox issues caused by malware
Hi all, thanks for the suggestions. I have to say that no 'single' one of these worked individually but together it fixed it. I downloaded and ran Malwarebytes - didn't fix Firefox but did show some threats which I removed. Restarted PC, Firefox still opened as clear window. Opened my Firewall and found no obvious reference to the web-browser; then found two 'allow' or 'trusted' references - removed those and still Firefox ran as a clear window. Ran Firefox in safe mode - starting with shift key worked (yesterday the 'run' command for safe mode was starting Firefox with the clear window as well) and it started. YAY!!! cos the thought of setting up Chrome to how I'd customised Firefox was doing my head in... There was no reference anywhere to Codec V1.0 and only one 'addictthing' plug in which I had disabled anyway over a week ago. I put Firefox through its update version, (even though I had downloaded and run an update trying to fix it yesterday) and let it restart Firefox normally instead of in safe mode, it started and I have let the Firewall go through its motions of 'allow this program'. Thank you for your help - its working again.