While creating OnApp products you may encounter Locale is invalid error. Error you've experienced is caused by HostBill trying to provision account in OnApp with client language from HostBill.
In order to solve this problem you need to:
- check client language in HostBill (the one that failed provisioning)
- check OnApp languages you have available
If you detected the problem you than need to add missing language into OnApp - even by creating copy of a missed language, but you have to name it correctly to relate to HB language.