Hi,
In the transaction code KEA0 while providing the Operating Concern currency in the attributes tab you should have been chosen from existing currency to press F4 entries.
But you have provided Currency US rather than USD manually. Here system not validates the existing currency. Does not matter existing currency or not existing (new currency) system allows to take currency.
As you said, you have not posted any transaction data. Until unless if there is no transaction currency it will allows you to change the operating concern currency in KEA0 transaction code.
Go to KEA0 Transaction code
click on attribute tab and click on change icon. it allows you to change the currency
Still if it is not changeable mode, please go and check the data in the below tables, If the data exists it will not allow
1. CE1****
2. CE2****
3. CE3****
4. CE4****
Please note that, **** is Operating concern.
Same thing you can check in KE24 transaction code also.
If the data exists for the above tables or T.code. I don't think so it will allow you even if you reverse the entries also.
I think in this juncture better contact SAP.
Ravi Polampalli