A new column will not allow checkin with workflow enabled - The file has been modified by error
When you create a library in SharePoint and have any fields that require user input such as a new column, the workflow will not allow a document to be uploaded. In my case I was using a choice column, I went back in to test with a single line of text as well with the same results.
Steps to replicate the issue.
1. Create new document library
2. Upload a document using the “Upload”
3. See it works
4. Add a workflow using SharePoint Designer 2013
5. Upload a document using the “Upload”
6. See it works
7. Add a new column
8. Upload a document using the “Upload”
9. See it prevents you to save it giving an error “The file has been modified by…” error, when the workflow starts automatically
To solve the issue, in SharePoint Designer, in 'Settings', uncheck "Automatically update the workflow stat to current stage name".
Calling Microsoft on this the answer was “No you cannot have a workflow on a library that has a field you would like to edit.” I didn’t think this was correct and found the answer above after some time.
Request is for the product team to look at the event when a new item is created and come up with a better means to start the workflow. Perhaps allow a moment for the item to be created before kicking off the workflow to allow the fields to be populated before the workflow checks them.