Where did you install Firefox from? Help Mozilla uncover 3rd party websites that offer problematic Firefox installation by taking part in our campaign. There will be swag, and you'll be featured in our blog if you manage to report at least 10 valid reports!

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Cannot install Lastpass add-on

  • 5 respostas
  • 1 has this problem
  • 37 views
  • Last reply by FredMcD

more options

Since upgrading to FF42 (now on FF43) I haven't been able to install FF - either from the add-on tab or from lastpass's site. I have done a FF clean install; I have done FF refresh. I can install on Chrome without issue, but firefox is my preferred browser. I have contacted Lastpass and they have tried to resolve the issue, but it installs for them without issue. I am on Windows 7.

The attached powerpoints show the error messages. If I try from the add-on page, I get "There was an error installing lastpass". If I use the link lastpass provided (https://addons.mozilla.org/en-US/firefox/addon/lastpass-password-manager/) I get "LastPass could not be installed because Firefox cannot modify the needed file).

Since upgrading to FF42 (now on FF43) I haven't been able to install FF - either from the add-on tab or from lastpass's site. I have done a FF clean install; I have done FF refresh. I can install on Chrome without issue, but firefox is my preferred browser. I have contacted Lastpass and they have tried to resolve the issue, but it installs for them without issue. I am on Windows 7. The attached powerpoints show the error messages. If I try from the add-on page, I get "There was an error installing lastpass". If I use the link lastpass provided (https://addons.mozilla.org/en-US/firefox/addon/lastpass-password-manager/) I get "LastPass could not be installed because Firefox cannot modify the needed file).

All Replies (5)

more options

This will disable add-on signature enforcement; Enter about:config into your Firefox address bar Click the I'll be careful button Find xpinstall.signatures.required in the list Right click the preference Select Toggle until the value is false https://support.mozilla.org/en-US/kb/add-on-signing-in-firefox

https://wiki.mozilla.org/Firefox/AddOns/Status/Updates#Exec_Summary “Currently targeting Signing with no pref to turn off in Firefox 47”

more options

Thanks Fred - have just tried this but same result - still cannot install and throws the same error messages.

more options

Contact their support site for more help, or a reason for the error.

more options

I did - and they routed me here. They have no idea what is causing it.

more options

I've called the big guys to help you. Good luck.