KB-1144 Appian attempts to overwrite files in accdocs folders after an upgrade


After an upgrade to a new version, you see errors in the application server log that state the system is attempting to overwrite files in the _admin\accdocs* folders. The server eventually fails to start. The log messages are similar to the one below:

INFO  [stdout] (ServerService Thread Pool -- 73) com.appiancorp.ix.ConsumerException: type=content, srcId=SYSTEM_CONTENT_ICON_INDICATOR_MOVE_DOWN, dstId=8668, cause=com.appiancorp.suiteapi.common.exceptions.AppianException: java.lang.IllegalArgumentException: Attempt to write over a file that already exists: ##PATH TO FILE IN ACCDOCS##, level=ERROR, object=ContentHaul[content=[Content:id=8668,name=iconIndicatorMoveDown,description=,type=1,uuid=SYSTEM_CONTENT_ICON_INDICATOR_MOVE_DOWN,parent=92,visibility=20,security=143,attributes={},partition=2147483647],resourceName=move_down.png,roleMap=com.appiancorp.suiteapi.content.ContentRoleMap@1565d0ce[

INFO  [stdout] (ServerService Thread Pool -- 73) Caused by: java.lang.IllegalArgumentException: Attempt to write over a file that already exists: ##PATH TO FILE IN ACCDOCS


This usually happens during upgrades with improper migrations or when the contents of the _admin folder have been moved around.

The cause for this is that the Collaboration engine has a mismatch with the _admin/accdocs folders. Specifically, the Collaboration engine has an internal counter that determines the next internal filename when creating a file. If the internal file already exists, then this will cause a conflict in the filename and the server may not start.


  1. If you are upgrading from a previous version, make sure that you copied the highest numbered engine database file *.kdb from the old directory to the new installation’s directory. If you move the *.kdb for any reason, you also have to move the contents of the _admin folder.
  2. In case of an unsuccessful upgrade, roll back to a backup from before the upgrade and attempt the migration again. Do not use the existing data to roll back, as there might be additional system files generated during the unsuccessful/partial upgrade attempt.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: March 2019