On a test server I have been trying to upgrade confluence from our current production version (2.6.3) to the current version. I successfully upgraded to 2.7.4 but when I try to upgrade to 3.5.17 I get:
2012-12-04 09:17:29 (EventLevel: error) (EventType: upgrade) Upgrade failed. Please consult the system logs for details. You will need to fix these problems, restore your database and confluence home directory to the pre upgrade state. Then retry the upgrade.
The log file has the following:
2012-12-03 15:50:21,677 ERROR main apache.catalina.session.ManagerBase doLoad IOException while loading persisted sessio
ns: java.io.InvalidClassException: com.atlassian.user.impl.DefaultUser; local class incompatible: stream classdesc serialVer
sionUID = 5446367461173827654, local class serialVersionUID = -4812692384151363809
java.io.InvalidClassException: com.atlassian.user.impl.DefaultUser; local class incompatible: stream classdesc serialVersion
UID = 5446367461173827654, local class serialVersionUID = -4812692384151363809
I tried searching the KB but the link that I found lead back to the search page. Should I be using a different release to do the upgrade? I'm really new to confluence and am still learning the ropes, so please forgive my ignorance.