Further analysis revealed a root cause: when a previous download was canceled for a specific *Incremental-table on Exact Online, next downloads might either fail within a second or keep hanging forever.
Cancelation of downloads typically occur:
- due to a time-out (
itgenboe147, avoid as described in What are the critical points for implementing Power BI?) - due to an error or user cancelation in Power BI Desktop.
Especially the last scenario can cause intermittent issues. For instance, Power BI Desktop downloads 8 requests at the same time. If any of these 8 fails, all other 7 will be canceled. Each of these cancelations had a small risk of triggering the issue, typically failing many or all future downloads of the table.
In general we also strongly recommend to increase the time-out on all OData4-downloads, even for the most small ones. Even very small downloads may have to wait on other large downloads to complete before a download channel becomes available.
A bug fix expected to solve the root cause found is planned to go live on March 28, 2024.
This bug fix should solve all these issues, but it is possible that another root cause has been overseen. So if the problem still occurs after March 28, 2024, please raise a new topic.