This has been an issue since the Original April Release. I continue to revert to the March 10th release as it is the last release that allows me to refresh my data.
I just tried the latest May release and the issue persists...
I have received two similar error messages between my two data models:
First: "DataFormat.Error: You attempted to open a database that is already opened by user 'Admin' on machine 'xxxxxxx'. Try again when the database is available."
Second: "DataFormat.Error: The database has been placed in a state by user 'Admin' on machine 'xxxxxxx' that prevents it from being opened or locked."
I have found that the error only occurs when refreshing from a database that sits on our network drive - I am using an Access Database as the datasource and if I copy the database to my local machine and redirect the datasource in Power BI Desktop, then the model refreshes without issue.
Please fix this issue - having to copy the database locally on my machine in order to refresh is not a viable work around. I continue to run the March 10th release until this is fixed, wishing that I could access some of the new features that were introduced in April and May...