Not fetching specific currencies on Magento (sometimes randomly)
We've developed an extension for Magento 1 some time ago that allows fetching currency rates from different sources, incl. Yahoo.
Currently some currencies simply don't work, though they're available on the website. Here's an example:
When requesting a EUR to USD rate, everything seems okay. But when we request EUR to BGN the rates aren't getting fetched and it returns an error:
{"chart":{"result":null,"error":{"code":"Not Found","description":"Encountered an error when generating the download data"}}}
The request looks like this:
https://query1.finance.yahoo.com/v7/finance/download/EURBGN=X?period1=1522022400&period2=1522071168&interval=1d&events=history&crumb=HKE.ti8xvR4
This also happens from time to time to other currency rates, but the BGN doesn't get updated under any circumstances, which is a bit strange (though these rates are present on the web version).
Any idea on what's the reason of the error and how to solve the issue?
Thanks