I find that sometimes this message is not entirely true.
When either symbol or exchange/destination is not set, or not valid, or not permissioned to the account being used, at the point when "PriceType"/"OrderType" is set, it will not actually be set, and when the order is submitted after, the result will be "PriceType is required". Perhaps this is what you are seeing.
If so, verify OrderType/PriceType is actually set. To be sure, symbol and destination have to be set, valid and premissioned to the account, prior to this set.
Hope this helps
I was wondering how I can stop making the Bid, ASK and Last field automatically populate from the REDI API in my order entry tool in excel, it might be coded into the VBA somewhere in the sheet, i am not sure how to fix it