Unable to process template language expressions for action 'Apply_to_each_sftp_file' at line '1' and column '30517': 'The template language expression 'body('List_files_in_folder')?['body']' cannot be evaluated because property 'body' cannot be selected. Array elements can only be selected using an integer index. Please see https://aka.ms/logicexpressions for usage details.'.

From one day to the next one of my flows stopped working with the error above. The flow is super simple:
Get files from an SFTP folder
Loop through the files
Copy file to another location
Delete file

Looking at the apply to each step I noticed body element was referenced. This might have been related to how I set up the loop or the autogenerated action.

Action the flow was unhappy with:

Updated the flow and it started working:

Note how the ?[‘body’] element is missing from the second picture.

Fix?
Created a new Apply to each loop by first setting a variable to the name of the file I’m looping on, then added my other actions. There might be a better way to fix this, but for now, this is what works.