Error 500 after upgrading Confluence to 5.2.x

Background

After we upgraded our Confluence instance from 5.1.5 to 5.2.5 we got surprised when trying to access the newly upgraded instance.

Instead of being greeted with the login screen, the webpage showed an Error 500 and Confluence wasn’t accessible at all.

Analysis

As usual the first step when running into problems with Confluence is to take a look at the Confluence log. This showed reoccurring errors like the following:

Searching the web pointed out a quite close issue described for the Support Tools Plugin (STP) “Upgrading to 3.5.20 results in a java.lang.AbstractMethodError”.

Support Tools Plugin is a bundled plugin in Confluence which provide some useful utilities for administrators like an automated log file scanner (which reports issues on a daily basis to admins) or a quick way to create support tickets.

The one issue with that report was that it was marked as resolved and was reported to having been occurred with version 3.5.20 of the plugin (while we were running 3.5.28). So did we really run into the same issue or was it simply a completely different problem we were facing?

Solution

After getting in touch with Lauretha Rura from Atlassian support and Deividi Luvison (who was assigned the Support Tools issue), Deividi confirmed that the compatible version number for STP versions > 3.5.20 was set incorrectly. While version 3.5.20 correctly stated it is compatible with Confluence >= 5.3 the following versions (including the one we use (3.5.28)) suggested they were compatible with Confluence >= 4.3. That’s how we ended up with that incompatible version of STP getting installed.

While this didn’t seem to be a problem with Confluence <= 5.1.5 with 5.2.5 it refused to work at all.

After having reported this to Deividi the incorrectly set compatibility versions of STP for Confluence were fixed, so that other users will no longer run into this problem.

Workaround

In case you are suffering the problem, the easiest way is to uninstall your current (incompatible) version of STP and install the latest compatible one (for Confluence 5.1.5 this would be STP 3.5.10 for instance) and perform the upgrade to Confleucen 5.2.x afterwards.

Alternatively, you can also directly upgrade to Confluence > 5.3 in which case the issue should not surface as well.