Not able to create a type of a variable from a end point

Summary

Facing issue while creating variable type from an endpoint

Content

I'm creating an application using VBCS Tool, For this task i'm creating service connection through REST Endpoint.  As you can see in the screenshot when selecting only string type or only object type able to create the variable type. The only issue I see when selecting mixed type like both string and object or selecting both string and array, In this case unable to create a type.
Earlier I was able to create such variables type but now seeing such error.  Am I making some mistake from my end while creating or there is a bug in the Tool.  Could you please give any suggestion how to fix it?