Hi,
It says the error like some files are msising, like
/home/platne/serwer19790/public_html/mrtb/wp-content/themes/xstore/framework/thirdparty/options-framework/extensions/fonts_uploader/extension_fonts_uploader.php
Download the theme from themeforest and login to your FTP and navigate to the above path and confirm that the file is present, if not, uplaod the same file in that path, and see that fixes the issue.
Let us know,
Thanks,
laranz.