Removing a Defect from a Test Run returns 500 internal error if the Test of the Test Run is covering another Test

Short Description: Removing a Defect from a Test Run returns 500 internal error if the Test of the Test Run is covering another Test.

Steps to Reproduce:

1 - Make sure your Test issue is a Coverable issue.

2 - Create a Test A with a step.

3 - Then, in the coverage section of the Test A, create a Test B.

4 - Create a Tets Run for Test A.

5 - Go to the Test run and add defects to the step and to the overal sectiom

6 - Remove them.

Actual Results: A 500 internal server error is displayed.

Expected Results: No error should be displayed.