No decision table reference key is defined on the dmn activity

When validating a process or case model containing a decision task in Flowable Modeler the validation error; "No decision table reference key is defined on the dmn activity" is always given. Even when a decision table / service is selected in the decision task.

This issue is only related that the validation. A false positive; when exporting / deploying the model is correct.

The validator needs to have a complete JsonConverterContext. This is currently not the case which causes this issue (not have the decision models available when looking up the key).