When you are querying data from BigQuery and encounter this error
Exec SQL failed: [{"message" : "Not found: Files /gdrive/id/......", "reason => notFound"}]
It looks like the table is linked to a Google Sheet and you will need to share that Google Sheet to the Google service account. The Google service account is the one that you create when connecting Holistics to Bigquery.
Just follow these step How to query Google Sheet via BigQuery and your issue would be resolved.