I keep encountering ClassNotFoundException errors ever since updating to Java 7 U5. Any help?
I am running Firefox 14. I have reinstalled both Java and Firefox to no avail.
I decided to once more uninstall both Firefox and Java and reinstall. This time it worked. I believe that the previous attempts to install Java failed for some reason. Anyway, thanks for the help.Read this answer in context 1
Additional System Details
- Shockwave Flash 11.3 r300
- Google Update
- NPRuntime Script Plug-in Library for Java(TM) Deploy
- Next Generation Java Plug-in 10.5.1 for Mozilla browsers
- The QuickTime Plugin allows you to view a wide variety of multimedia content in Web pages. For more information, visit the QuickTime Web site.
- iTunes Detector Plug-in
- Adobe PDF Plug-In For Firefox and Netscape 10.1.3
- npmnqmp 989898989877
- Adobe Shockwave for Director Netscape plug-in, version 11.6
- Best Buy pc app Detector Plug-in
- User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:14.0) Gecko/20100101 Firefox/14.0.1
You can try to delete the Temporary Internet Files in the Windows OS Control Panel > Java. If the problem persists you may also have to contact the applet developer.
The problem is bigger than any one applet developer. Java is not working at all, no matter which applet I am using. I did try all your suggestions and Java still is not working.
Does Java work on the Java test pages?
Does the latest Java 6U33 still work on those websites?
See Java Platform > Java 6U33 (Download JRE)
I decided to once more uninstall both Firefox and Java and reinstall. This time it worked. I believe that the previous attempts to install Java failed for some reason. Anyway, thanks for the help.
Exactly same problem: ClassNotFoundException error - and no, reinstalling Firefox 14 and Java 7u5 did not resolve it.
In my case the solution was:
disable plugins.click_to_play in about:config.
I had enabled this (set it to true) to take advantage of FF14's clicl-to-play functionality - but apparently it stops Java from working properly!