Hi @TheresePawlicki,
Could you please share a screenshot of your flow's configuration?
How do you create a connection to the File System connector within your flow?
The error message told that the On-premises data gateway could not be found within the connection to the File System connector on your side.
If you want to connect to File Systems on your local or network machines to read from and write to files within Microsoft Flow, you must use the On-premises Data Gateway. In addition, not just the File System connector, if you want to connect to other local servers (e.g. Local SQL Server, Local SharePoint site, etc.) within your flow, you should also use the On-premises Data Gateway to create a connection to these local server.
I have created a connection to the File System connector using the On-premises Data Gateway within my flow and the screenshot as below:
I have made a test on my side and please take a try with the following workaround:
The flow works successfully as below:
Please take a try to install a On-Premises Data Gateway on your side based on the following article:
On-premises Data Gateway for Microsoft Flow
More details about the File System connector, please check the following article:
File System connector
Best regards,
Kris