Localizartion issue

You should add the labels into the localization file…
Currently in the opensearchserver_search_functions.php file the labels title are hard coded instead of declaring it into the localization file ex.:
_e('Next', 'opensearchserver');

These are the only 4 strings hardcoded: First, Previous, Next, Last.

https://www.ads-software.com/plugins/opensearchserver-search/