Mozilla VPN is currently experiencing an outage. Our team is actively working to resolve the issue. Please check the status page for real-time updates. Thank you for your patience.

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. Please ask a new question if you need help.

Why don't java applets run when using Firefox 4.0 in a windows limited user account?

  • 1 reply
  • 37 have this problem
  • 6 views
  • Last reply by arg0710

arg0710
arg0710
more options

Java applications will not run in Firefox 4.0 when the windows user/process only has limited user access rights. The systems, I see this behaviour on have Windows XP Pro SP3, Firefox 4.0 and JRE 1.6.0_24 installed. The java application will run when when full administrative rights are present. This issue did not occur with the 3.6 firefox version that was previously installed.

Java applications will not run in Firefox 4.0 when the windows user/process only has limited user access rights. The systems, I see this behaviour on have Windows XP Pro SP3, Firefox 4.0 and JRE 1.6.0_24 installed. The java application will run when when full administrative rights are present. This issue did not occur with the 3.6 firefox version that was previously installed.

Modified by arg0710

All Replies (1)

arg0710
arg0710 Question owner
more options

The problem also exists with the newer Firefox 4.0.1 and Java 1.6.0_25 versions.

Enabling administrative rights resolves the issue ... though this defeats the purpose of using a limited user.

The underlying bug appears to be in the Firefox java plugin detection code. The issue is related to the detection code requiring write access to the HKLM\SOFTWARE\mozilla.org windows registry key. The limited user only has read access for this registry key. The behaviour was identified using the Sysinternals ProcessMonitor utility ... showed firefox calling an interface to create the registry key and getting an access denied response in the limited user case.

A more targeted workaround for the issue is to grant the limited user write access on the HKLM\SOFTWARE\mozilla.org windows registry key. This avoids the need to grant administrative rights to the user and enables the java plugin to be detected. That is, it works on the 2 XP systems where the java plugin wasn't being detected in limited user accounts.