Hi @D Williams
Welcome to Microsoft Q&A platform and thanks for posting your question here.
Based on the error message you provided, it seems that the copy activity is failing because the metadata field contains an invalid property name due to the accented characters in the filename. The error message specifically states that "The property name contains invalid characters."
To resolve this issue, you can try removing the accented characters from the metadata field value or replacing them with non-accented characters. This should allow the copy activity to complete successfully without encountering the "InvalidPropertyName" error.
Alternatively, you can try encoding the accented characters in the metadata field value using URL encoding or UTF-8 encoding. This may allow the copy activity to recognize the metadata field value as a valid property name.
Reference
https://learn.microsoft.com/en-us/dotnet/api/system.web.httputility.urlencode?view=net-8.0#system-web-httputility-urlencode(system-string-system-text-encoding)
I hope this helps! Let me know if you have any other questions.