Hi @Unif,
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.
Ask: Azure AI Search: How to Modify the document key to meet the validation requirements
Solution: I changed the filename to xxx/yyy/FILE_NAME/1
to avoid a double filename (which was in Non-English).
As a result, the error disappeared, and the indexing process of Azure AI Search was able to proceed correctly.
If I missed anything please let me know and I'd be happy to add it to my answer, or feel free to comment below with any additional information.
If you have any other questions, please let me know. Thank you again for your time and patience throughout this issue.
Please don’t forget to Accept Answer
and Yes
for "was this answer helpful" wherever the information provided helps you, this can be beneficial to other community members.