Hello @IniVismiM
What is your transaction currency? Is it other than OMR? If so, you need to define rate for other currencies in rate type 3. Here is help text how Transaction Currency base works.
Parallel Currency Base
The currency base used to calculate amounts in parallel currency for the company. If Transaction Currency is selected, parallel currency amounts are calculated based on the currency in which the relevant transactions are carried out. If Accounting Currency is selected, parallel currency amounts are calculated based on the currency entered as the company's accounting currency.
Hope this helps
Hello @IniVismiM
Yes, as mentioned by Gumabs, since the parallel currency based is set to Transaction Currency, check on the currency transactions take place and define rate(s) accordingly.
Hopefully this should resolve the error.