Hi @yna4ever ,
There are several points you may considerate:
1.Your data source credential may expire, so try to update the credential and republish the report. In Power BI, go to refresh settings for the dataset. In Manage Data Sources, select Edit credentials to update the credentials for the data source.
2.If your dataset not only contains cloud data source but also the on premise data source, then it needs to use the gateway and configure schedule refresh, see more: :On-premises data gateway , Configure scheduled refresh .
Note that you also need to select Allow user's cloud data sources to refresh through this gateway cluster option Under Gateway Cluster Settings. See: Merge or append on-premises and cloud data sources.
3.Ensure that you've added one or more data sources of your dataset to the gateway, as described in Add a data source.
4.Please make sure the gateway is online, and try to upgrade the gateway to latest version.
5.Please set schedule refresh for different datasets at different times, make sure that you don't schedule more than max parallel refreshes for the different nodes in these capacities. Also we suggest that you first disable all refreshes on all capacities. Then slowly enable the refreshes one by one. Make sure refreshes are staggered apart (e.g. 1 hour apart), and that no more than max concurrent refreshes happen at overlapping time periods.
6.Power BI Pro or Power BI Free supports uploading Power BI Desktop (.PBIX) files that are up to 1 GB in size.
Power BI Premium supports uploading Power BI Desktop (.PBIX) files that are up to 10 GB in size.
If you need to upload PBIX file that is larger than 10 GB, consider to move data from your source to SQL Server, Oracle or SSAS, then use DirectQuery/Live connection.
You may resolve the issue via the troubleshooting link :https://docs.microsoft.com/en-us/power-bi/refresh-troubleshooting-refresh-scenarios .
Community Support Team _ Amy
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