Recently, I was informed that one of our Power BI Datasets could not be refreshed due to an error, and that the schedule had been turned off as a result. The error that was in the refresh history was similar to the one shown below.
It appeared that something was causing a timeout on the Power BI gateway.
I opened the dataset in Power BI Desktop, and refreshed the queries manually to see if a similar error was thrown. Though the queries took about an hour to complete, there was no error. I found the timeout setting for the data source and saw that it was blank. I thought, being relatively new to Power BI still, that this timeout needed to be set, so I set it for 60 minutes, just to test. Still no error when refreshing manually, but when published to the Power BI service, the same error remained.
There were three queries in the dataset, and as it turns out, three separate timeout values. The data source for each query had to changed individually. When I deleted the timeout settings from all three queries and republished the dataset, it was able to be refreshed on schedule without issue.
This should be the first step in troubleshooting future timeout issues, as this is can be a quick fix for this type of problem.