I assume that this is an upgrade.
You have custom syncmappings which are not compatible with changes made to the syncmappings in 11.0. They were changed to handle the new cluster model and remove much of the old code duplication. In order to allow upgrades you need to update them.
It is probably easiest to deactivate your custom mappings. Update the TKU and then modify and update your syncmappings.
That was indeed our problem. Thanks for helping out!