Piksal

TDO Mini Forms is a great plugin for Wordpress , allows you to add highly customisable forms that work with your Wordpress Theme to your website that allows non-registered users and/or subscribers (also configurable) to submit and edit posts and pages.

However, when I tried to edit the “messages” option in Vietnamese (or other non-latin languages) and then saved it, the error occured telling me nothing and eventually reset all the messages to the default ones.

the solution is simple, all you need to do is to change the collation of the field “form_options” in table “wp_tdomf_table_forms” in the database to “utf8_general_ci”.

and done! problem solved.