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I keep encountering ClassNotFoundException errors ever since updating to Java 7 U5. Any help?

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  • 47 have this problem
  • 44799 views
  • Last reply by discs

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I am running Firefox 14. I have reinstalled both Java and Firefox to no avail.

Chosen solution

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.

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Hi,

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.

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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.

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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)

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Chosen Solution

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.

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SOLUTION!

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!