Comments / questions?
Common issues
If you're seeing a message like this, the most likely cause is that Google has internally cached a bad response:

To fix it, you can append a query string to the URL, by adding a ? and then any random text, like this:
https://cryptorates.ai/files/standard.csv?blahblah
=QUERY(IMPORTDATA("https://cryptorates.ai/files/standard.csv?blahblah", ",", "en_US"), "SELECT Col3 WHERE Col1 = 'BTC'", 0)This will cause Google to re-fetch the data, and bypass the invalid response they have previously cached.
Note: Please make sure to not use blahblah as I have used there, but pick any random text of your own.
Anything else
For any issues or questions, please raise them here: Github issue tracker
