Cannot migrate from redmine to selfhosted taiga

[cornerot]

Hello.
Redmine version : 2.0.2.stable

I see all the redmine projects in the migrator, but get an error when starting migration:

2018-06-27 16:00:21.050 ERROR - org.apache.log4j.Category$error$1Exception while migrating: Cannot get property 'contentAsString' on null object
2018-06-27 16:00:21.052 DEBUG - org.viewaframework.widget.view.ui.MasterViewModel[M:11 | V:11] gui.console.ConsoleViewEntry(ERROR, gui.controller.MigrationProgressAwareController, Exception while migrating: Cannot get property 'contentAsString' on null object, Wed Jun 27 16:00:21 MSK 2018)