We're seeing SizeLimitError.REQUEST_SIZE_LIMIT_EXCEEDED errors on mutate operations to the campaign criterion service.
We're sending them in chunks of at most 50 operations, and the total number of operations is around 300.
We're not using the Bulk service.
This seems to affect only one of our AdWords accounts. The others work with the same chunk size.
We previously had a similar error which we "fixed" by reducing chunk size from 100 to 50.
I don't know if this is related, but the last occurrence coincided with someone creating a large number (thousands) of location bid adjustments on campaigns from AdWords Editor.
It would be helpful to know why we're getting this error, and why different accounts seem to have different request size limits.