Error message when attempting to refresh data.

Hey, I don't know why this is happening, but when I try to manually refresh Excel data, it comes up with a caution sign with the technical details stating: "The database with the name of 'Long ID', ID of 'Long ID' is read only and cannot be processed."; with 'Long ID' being the particular series of numbers and characters separated by a few dashes.

The problem is; I did not set the Excel sheet to be read-only; so I cannot understand why this kind of a issue would come up. Even then, if Excel is read only; the point of PowerBI is to read data from Excel and then allow the user to process that data into visualizations; so why would it even complain if all it needs to do is read from the Excel sheet?

Some clarification and troubleshooting would be much appreciated on this. Thank you.

-Alex b.