Recently, while we updated a Power Apps for a client, we came across with an issue with the Attachments control.
Without making any changes in the attachment control, all of sudden, it was showing “Unknown Error occured”, when the list item does not have attachments.
After digging a little bit we found out there was a bug in the latest version released by Microsoft. The only option was to downgrade to a previous version of the Power Apps Studio and save the app.
When you edit a Canvas app from make.powerapps.com you are working with Power Apps Studio. Microsoft keeps rolling out updates on a regular basis. So, authoring version is nothing but the version you are using to create your app in the Power Apps Studio.
How to change it?
Open any of your existing canvas app in the Power Apps Studio using the ‘Edit‘ button. Under File menu, you will find ‘Account‘ as an option; click that and your screen will look like below.
Click on the link that says “Change authoring version”. This will display a popup with list of versions; one would be the recommended version. Select your preferred version and click the button that states “Reload + apply version”. This will close the current app and reopen in edit mode with the updated version that you selected.