The Facebook Ads bidding and budget information may seem to work in mysterious ways, especially when you are trying to generate a report from the API. Here is a picture of how it fits together. More
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Please reduce the amount of data you’re asking for
When the Facebook Ads API returns an error 500, it is usually telling you that the combination of the number of metrics and rows of data being asked for is too large for them to process all at once. You may hit the limit around 1000 rows, or it could be higher or lower depending on the number of columns you are asking for. More