If you're importing a .csv (or .xlsx) file into a Google Maps map, you may have seen an error like an error occurred, your last action was reverted.
Unfortunately, there doesn't seem to be official word on all the situations under which that happens and what the estimated timeframe is for a full fix (even if the functionality isn't fixed, a more informative error message would certainly help).
Here are a couple of threads on the matter:
Creating New Layer in My Maps "An error occurred, your last action was reverted"
Error Importing Spreadsheet: "An Error occurred, your last action was reverted."
I don't know that this will work for all or even most situations, but we had this come up here once, and the issue was selecting too many address/location fields.
So, if you've had experience checking all the fields and it working, sometimes it does appear to work. Other times, if you check all the fields...
... you may later get this error before the import finishes...