Hi
I coulndt find a lot using the error msg. Just that the system again checks the allocation structure during creation of settlement rule from table TKB5A.
However I do have one theory..
You've mentioned that this issue is not occuring for other Orders. Question: Did anyone change the config for allocation structures or its assignment to the Settlement profile / Order type recently? I am guessing that could have had an impact. Its just a guess!
You can check the config changes using transaction SCU3 - table log changes, The table for the allocation structure config is CO_SSTRCV1. & its assignment to settlement profile table is TKB1V.
Hope that helps
Regards
Sumeet
