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Why is my browser detected as old at: https://www.mozilla.org/en-US/plugincheck/

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  • Last reply by John99

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https://www.mozilla.org/en-US/plugincheck/ tells me my browser is an older version. But the "about-box" tells me it's already updated. Any ideas what I could do? (besides resetting & losing all addons etc.)

https://www.mozilla.org/en-US/plugincheck/ tells me my browser is an older version. But the "about-box" tells me it's already updated. Any ideas what I could do? (besides resetting & losing all addons etc.)

Chosen solution

If you are posting form that machine then either it is an old Fx49 or your browser is providing the wrong UAS as the forum software is detecting it as

  • User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:49.0) Gecko/20100101 Firefox/49.0

You do not list your add-ons so maybe you have an extension that is switching that. Or maybe it indicates a malware or adware issue. if you paste your information from the Troubleshooting Information Page in to a reply it may help determine what is happening. That is a long list. If it contains print related information edit that out as it is not relevant.


To find the correct solution to your problem, we need some more non-personal information from you. Please do the following:

  1. Use ONE of these methods to open the Firefox Troubleshooting Information page:
    • Click the menu button New Fx Menu, click on help Help-29 and select Troubleshooting Information.
    • Type about:support into the Firefox address bar and press the enter key.
  2. At the top of the Troubleshooting Information page that comes up, you should see a button that says "Copy text to clipboard". Click it.
  3. Now, go back to your forum post, right-click in the reply box and select Paste from the context menu (or else click inside the reply box and press the Ctrl+V keys) to paste all the information you copied into the forum post.

If you need further information about the Troubleshooting information page, please read the article Use the Troubleshooting Information page to help fix Firefox issues.

Thanks in advance for your help!

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Chosen Solution

If you are posting form that machine then either it is an old Fx49 or your browser is providing the wrong UAS as the forum software is detecting it as

  • User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:49.0) Gecko/20100101 Firefox/49.0

You do not list your add-ons so maybe you have an extension that is switching that. Or maybe it indicates a malware or adware issue. if you paste your information from the Troubleshooting Information Page in to a reply it may help determine what is happening. That is a long list. If it contains print related information edit that out as it is not relevant.


To find the correct solution to your problem, we need some more non-personal information from you. Please do the following:

  1. Use ONE of these methods to open the Firefox Troubleshooting Information page:
    • Click the menu button New Fx Menu, click on help Help-29 and select Troubleshooting Information.
    • Type about:support into the Firefox address bar and press the enter key.
  2. At the top of the Troubleshooting Information page that comes up, you should see a button that says "Copy text to clipboard". Click it.
  3. Now, go back to your forum post, right-click in the reply box and select Paste from the context menu (or else click inside the reply box and press the Ctrl+V keys) to paste all the information you copied into the forum post.

If you need further information about the Troubleshooting information page, please read the article Use the Troubleshooting Information page to help fix Firefox issues.

Thanks in advance for your help!