Error when trying to remove test cases from a test execution

A user possessing the necessary permissions is unable to remove existing Test Cases from a Test Execution issue, receiving an error instead of the expected outcome.

Steps to reproduce:

1. Create a test execution
2. Create one test
3. Add the test to the test execution
4. Remove the test from the test execution

Actual Result: An error is shown and the test is not removed from the test execution{}

Expected Result: The test is removed from the test execution