I'm sharing the solution to this problem because I couldn't find it anywhere.
So this is the error message. At first glance, it seems that the issue is with the `replace` function but of course it isn't.
The input to the `replace` function is the contents of a CSV file that is stored in OneDrive, which is retrieved using the Get_file_content_using_path action.
It turns out that one of the following has changed:
- the output from Get_file_content_using_path no longer returns a string, but an object, OR
- the conversion from the output of said action no longer automatically extracts the string value.
The solution is to add a Compose action to convert the output of Get_file_content_using_path to get its string contents.
The Compose action gets the contents of the output and unencodes the Base64 representation using this function:
base64ToString(body('Get_file_content_using_path')?['$content'])
That's it.
The solution was only obtained by checking the output of `actions('Get_file_content_using_path')`
What's frustrating about this error is that this flow that I had created in July 2025 had been working fine all along until 12 March 2026.
Something changed on this platform with no warning and the flow just failed.
