Refresh Timeout Error.

Hi. Power Bi Pro has a limit of 2 hours to refresh your data.if you exceed that time you can't continue. This can happen for different reasons like bandwitdh (if you have a gateway) or dataset size.

You have to consider reading about downsizing data model. You can find amazing youtube videos from guy in a cube and others in order to make your model smaller. Usually making a good star schema helps.

Another thing you can check is if your source is returning the data fast. You might have a big crazy native query to the source that takes a lot. Those scenarios might need a middle store procedure building a table in the data base engine in order to help Power Bi only reading the resulted table and avoiding running a complex query.

If you are on premise you can also check bandwidth but that might be the last option because the first two I have mentioned are the most common issues.

I hope that make sense,