'java.lang.ClassFormatError - Incompatible Magic Value' When Adding a Patch Due to Invalid Download
Platform Notice: Data Center Only - This article only applies to Atlassian products on the Data Center platform.
Note that this KB was created for the Data Center version of the product. Data Center KBs for non-Data-Center-specific features may also work for Server versions of the product, however they have not been tested. Support for Server* products ended on February 15th 2024. If you are running a Server product, you can visit the Atlassian Server end of support announcement to review your migration options.
*Except Fisheye and Crucible
Symptoms
In some cases Support staff may give customers a patched class to add to their instance that will correct an issue or add extra debugging. After deploying this class and restarting, Confluence fails to start with the error message:
1
nested exception is java.lang.ClassFormatError: Incompatible magic value 3199925962 in class file com/atlassian/confluence/user/PersonalInformation
Cause
Certain browsers will corrupt class files when downloading them.
Resolution
Ask Support to zip the class file first before uploading it
Or, use another browser to download the file
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