Cannot install any add-ons
This is the error message. Firefox could not install the file at
because: Unexpected installation error Review the Error Console log for more details. -203
Alle antwurden (1)
-> Tap ALT key or press F10 to show the Menu Bar
-> go to Help Menu -> select "Restart with Add-ons Disabled"
Firefox will close then it will open up with just basic Firefox. Now do this:
-> Update Firefox to the latest version by going to Help Menu -> About Firefox -> click Check for Updates -> if an updated version is found then download the latest version and install it. After that follow these steps:
-> Update ALL your Firefox Plug-ins https://www.mozilla.com/en-US/plugincheck/
-> go to View Menu -> Zoom -> click Reset -> Page Style -> select Basic Page Style
-> go to View Menu -> Toolbars -> unselect All Incompatible/Unwanted toolbars
-> go to Tools Menu -> Clear Recent History -> Time range to clear: select EVERYTHING -> click Details (small arrow) button -> place Checkmarks on Cookies, Cache -> click Clear Now
-> go to Tools Menu -> Options -> Security -> place Checkmarks on:
1) Warn me when sites try to install add-ons 2) Block reported attack sites 3) Block reported web forgeries 4) Remember Passwords for sites
-> go to Tools Menu -> Options -> Advanced -> Network -> Offline Storage (Cache): click Clear Now button
-> Click OK on Options window
-> click the Favicon on SearchBar -> click Manage Search Engines -> select all Unwanted Search Engines and click Remove -> click OK
-> go to Tools Menu -> Add-ons -> Extensions section -> REMOVE All Unwanted/Suspicious Extensions (Add-ons) -> Restart Firefox
-> go to Tools Menu -> Add-ons -> Appearance section -> REMOVE All Incompatible/Unwanted/Suspicious Themes (Persona) -> Restart Firefox
You can enable your Known & Trustworthy Add-ons and Themes later. Check and tell if its working.