Hi @weird_guy,
In reference to the QS language, unfortunately there’s no documentation that breaks down the error codes you may receive (in my opinion, the error messages could use some updating to help users diagnose the issue better!). In terms of help for learning more about how to better build and utilize the advantages of calculated fields, this is the best article I’ve found for furthering that knowledge!
Looking at your calculation; what is the field type for ‘order_id’, is it a string? If so, I believe that’s where your error is coming in as you’re unable to sum string values. Do you have an additional field in your dataset that contains the amounts you’re trying to sum or are you trying to get gather a count of order id’s?
If trying to utilize a count of order id’s in the calculation, you’ll half to first build out a separate calc. field to complete that; which in that case, I would check out the DistinctCountOver function.