@LXF I'm glad that you were able to resolve your issue and thank you for posting your solution so that others experiencing the same thing can easily reference this! Since the Microsoft Q&A community has a policy that "The question author cannot accept their own answer. They can only accept answers by others ", I'll repost your solution in case you'd like to "Accept " the answer.
Issue: I encountered an error "u.dataTypes is undefined" when importing a CCP on Sentinel.
Resolution: Resolved by @LXF by following these steps
the hint from github readme (https://github.com/Azure/Azure-Sentinel/blob/master/DataConnectors/ReadMe.md) that "be sure to only upload a json file containing the connectorUiConfig collection.", rather then importing a complete CCP json document.
If you have any other questions or are still running into more issues, please let me know. Thank you again for your time and patience throughout this issue.
Please remember to "Accept Answer" if any answer/reply helped, so that others in the community facing similar issues can easily find the solution.