When importing test execution result containing german special character gives error: deserializing results file

When importing test execution results throwing an error when it's containing :

• German umlauts like ä, ö, or ü.
• Test cases containing double inverted commas, and names of the robot test cases containing &.
• Tags used in the Robot test cases containing ß (Eszett, spoken like s)
• It also doesn't accept Chinese letters ("罗/羅","中國") (mentioned in sample.json file).

How to reproduce

1. Create Test execution.
2. Generate XML result using Robot framework which should contain German umlaut, double inverted comma, and test case name contains &.
3. Import test execution results using the import test execution result option on UI or Using REST API.

Actual result/Attachments:

{"error": "Error de-serializing Robot file."}

Expected result:

Execution result imported successfully.