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Firefox becomes useless

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  • 2 have this problem
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  • Last reply by cor-el

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After updating Firefox 90% of all websites are suddenly insecure and I recieve the following message: Deze verbinding is niet beveiligd. This seems a problem with the update as before the update there was no issue at all with these websites and Firefox.

After updating Firefox 90% of all websites are suddenly insecure and I recieve the following message: Deze verbinding is niet beveiligd. This seems a problem with the update as before the update there was no issue at all with these websites and Firefox.

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Do you use security software that filters your web traffic, for example, Kaspersky, BitDefender, avast!, or ESET? Firefox might no longer be set up to trust the software (in order to decrypt and scan your secure connections, the software needs to present fake certificates to Firefox).

During your update, did you by any chance use the "Refresh" feature? This might occur if Firefox detects that it is performing poorly, and offers the option to speed it up by restoring some default settings. The best indication is that an "Old Firefox Data" folder appears on your desktop. Do you see anything like that?

If so, that would explain why Firefox lost the ability to trust the fake certificates, and you'll need to set that up again. The easiest method depends on which software it is. Can we help you look that up or would you prefer to check the security software vendor's support site or user guides?

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Do you have this problem on the Mac computer that you used to post this question?

Check the date and time and time zone in the clock on your computer.

You can check the connection settings.

If you do not need to use a proxy to connect to internet then try to select "No Proxy" if "Use the system proxy settings" or one of the others do not work properly.

See "Firefox connection settings":