Database migration fails - Unsupported major.minor version

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

Attempting to migrate to SQL Server using a downloaded driver the test connection procedure hangs. The following appears in the atlassian-fisheye-<YYYY>-<MM>-<DD>.log:

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 Caused by: java.lang.UnsupportedClassVersionError: net/sourceforge/jtds/jdbc/Driver : Unsupported major.minor version 51.0 at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631) at java.lang.ClassLoader.defineClass(ClassLoader.java:615) at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141) at java.net.URLClassLoader.defineClass(URLClassLoader.java:283) at java.net.URLClassLoader.access$000(URLClassLoader.java:58) at java.net.URLClassLoader$1.run(URLClassLoader.java:197) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:190) at java.lang.ClassLoader.loadClass(ClassLoader.java:306) at java.lang.ClassLoader.loadClass(ClassLoader.java:247) at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:249) at com.atlassian.crucible.actions.admin.database.TestDBConnectionAjaxAction.checkDriverClass(TestDBConnectionAjaxAction.java:53) at com.atlassian.crucible.actions.admin.database.TestDBConnectionAjaxAction.execute(TestDBConnectionAjaxAction.java:27) ... 113 more

Cause

There is a mismatch between the driver and Java version.

Resolution

Make sure the driver is compatible with the installed Java version. See this

Stackoverflow article

.

Updated on April 8, 2025

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