This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Avatar for Username

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

This thread was archived. Əgər kömək lazımdırsa lütfən yeni sual verin.

Firefox won't redirect custom protocols to their programs

  • 2 cavab
  • 2 have this problem
  • 1 view
  • Last reply by RashanH

Dan
Dan
more options

Every time I try to go to a custom protocol URL to get redirected to a program for things like website sign-in I get this error page instead of it working or offering the program selector. "The address wasn’t understood

Firefox doesn’t know how to open this address, because one of the following protocols (cag) isn’t associated with any program or is not allowed in this context. 

   You might need to install other software to open this address."

The protocol shows up in the applications setting and is pointed to the correct program. I have made sure my Firefox and Windows 10 are fully up to date. I tried launching Firefox in safe mode. I actually completely reinstalled my computer. It works briefly until a little after sync completes but the computer it is syncing from does not have this issue.

This issue has occurred so far with Slack and Datto RMM.

Any help would be fantastic!

Every time I try to go to a custom protocol URL to get redirected to a program for things like website sign-in I get this error page instead of it working or offering the program selector. "The address wasn’t understood Firefox doesn’t know how to open this address, because one of the following protocols (cag) isn’t associated with any program or is not allowed in this context. You might need to install other software to open this address." The protocol shows up in the applications setting and is pointed to the correct program. I have made sure my Firefox and Windows 10 are fully up to date. I tried launching Firefox in safe mode. I actually completely reinstalled my computer. It works briefly until a little after sync completes but the computer it is syncing from does not have this issue. This issue has occurred so far with Slack and Datto RMM. Any help would be fantastic!

All Replies (2)

Dan
Dan Question owner
more options

Just a side note, this has been tested and works in Chrome and Internet Explorer

RashanH
RashanH
more options

Hello Dan,

Someone has posted about this kind of issue yesterday. Hope this will be fixed by FF developers.