Form multi language error messages

Hi,
is there a way to translate the Validation error message in Form Fields in OS Membership PRO?
There does not seem to be equivalents in the Translation tab.
I tried to add a translation string (i. e. OSM_FIELD_REQUIRED), but this didn't work, either.
Any ideas?

Kind regards,
Bernhard

Could you please take a screenshot of the error message you are talking about so that I can look at it to understand your question and give you the answer?

Tuan

Hi Tuan,

please, see this screenshots:





Added i. e. OSM_FIELD_REQUIRED to Joomla's language overrides. Didn't work either.

Thanks for your help.
Kind regards,
Bernhard