"There are too many Exports running at the same time belonging to this account"
This error occurs when you have too many Exports scheduled at the same time in the same account. The reason behind this is that every account can only make a limited amount of queries per minute.
To avoid this error you can
Schedule the Exports at different times
Decrease the date range of the Export
Disable or delete unused Exports
"This Export contains a data source ... with too much data"
A data source in the Export contains too much data to be exported.
To avoid this error you can either
"Edit configuration" of the data source in the Data Sources page to include fewer data (eg. fewer dimensions)
Exclude it by filtering out the data source from the Funnel Data Export
I can't open the gzip (.gz) files
If you can't open the gzip file that we export to your Data Warehouse and you are using Mac then the reason is most likely a long-running bug in the macOS Archive Utility that mistakes it for the wrong file type (mtree).
To avoid this error
Use something else than the built-in macOS software to un-gzip the file