It gives an error when I search by a location field through the Veronika theme on the main page. With other links all is normal. This error appeared when I put manual locations (countries, regions, cities), and at the same time turned on and off the permalinks (to see how it works).

Version osclass 3.7.4, php - 5.6 (semingly), hosting is eurobytes.

It is a link to the problem - http://ivia.tk/index.php?page=search&cookieAction=done&sCountry=US&term=United%25252525252525252525252525252525252525252BStates


On the images you can see that it all works and the same search by locations as on the main page on the second page works correctly.

It works on other themes (I checked by osclass wizards 2.0.4), but in veronika it does not.

Debuger shows nothing.

May be it is something in mysql?

Clear browser cache and try again 

@Eugeniu Nazaria
It seems there is problem with your URLs. It may be problem of encoding, htaccess issue, modifications in friendly URLs or corrupted osclass installation.

If you enter word white space (United States) into any search box (term, pattern...), it will result on bad page:
http://ivia.tk/index.php?page=search&term=United%25252525252525252525252525252525252525252BStates

however correct one is:
http://ivia.tk/index.php?page=search&term=united+states

(if you enter correct one, you are redirected to incorrect one)

You could use URL encode format to be correct, encoded white space has sign: %20
That is not happening on your site. (try: https://meyerweb.com/eric/tools/dencoder/)

Do you use own server or something like that? try to talk with your hosting provider, yet I see such issue maybe once in last 3 years.