Hi,
The error is related to only Revenue Account determination. Your revenue account requires to check if you have V/KOFI/Chart of Accounts/sales organization/Account assignment Group Customer/Account Assignment Group material is correct. It should be attached with correct Account Keys like ERL, ERF, ERB, EVV, MWS for tax. any times if you do not set up Tax in SD & FICO error comes. Check if FTXP is correct with assignment of G/L accounts for all taxes.
As item category is service item please check if you have account assignment group for material as correct 02. Secondly I think you should also have KOFK to be assigned as service item is having KOFK many times. Please work & still any issue send screenshots especially Revenue Account determination and the condition (by clicking magnifying lens) Check Tab account determination and see if you have Tax code, G/L account etc. Hope this will help you.
Thankss