If you go to our Open Geography portal here - https://geoportal.statistics.gov.uk/datasets/local-authority-districts-may-2021-uk-bfc/explore?locat...
and click on the Download button and if you click on Download it says file generation in Progress and the it says file generation error on all 4 available downloads. This has been happening recently on most of the boundaries we have uploaded recently.
The KML and GeoJSON ones all keep failing but the CSV and Shapefiles seem to be downloading fine.
Check out the new International Territorial Level 2 Boundaries https://geoportal.statistics.gov.uk/datasets/international-territorial-level-2-may-2021-uk-bfc/explo...
and click on the Download button and if you click on Download it says file generation in Progress and the it says file generation error on 2 of the available downloads - KML and GeoJSON downloads.
We had similar issues with some of our larger polygon datasets in our organization, as well. After some lengthy troubleshooting with Esri support, we found some things that helped, though we're still encountering some unexpected behavior.
In the layer's item page, open settings, and set the following:
1. Check "Keep track of created and updated features." Even if you don't regularly modify the layer, this lets Hub/Open Data Portal know whether the cached copy of the download needs to be replaced, which can save your users a LOT of time.
2. Click the "Optimize layers" button, check the box next to the layer name in the popup, click "Update". This improves the performance of large datasets in general, but it does increase the online storage footprint significantly.
3. Check the box next to "Allow others to export to different formats." This allows users to download the layer in an file geodatabase, and is supposed to improve performance on downloading other file types.
4. Click the "Rebuild Indexes" button, check the box next to the layer name in the popup, click "Rebuild". I guess up-to-date indexes help the layer export code work better? It doesn't make much sense to me, but when one of our layers stopped working recently, running this again fixed it, even though the layer hadn't otherwise changed so much as a single byte.
The tech support rep recommended un-sharing the layer while making these changes, as some of them can take a few minutes.