Can't run Cron due to the PHP theme errors - workaround

I can't run cron on the website due to the following PHP warning. (PHP 7.1)

Warning: Illegal string offset 'content' in dexp_shortcodes_carousels() (line 13 of \sites\all\modules\drupalexp\modules\dexp_shortcodes\includes\carousel.inc). Warning: A non-numeric value encountered in theme() (line 1088 of \includes\theme.inc). Error: Unsupported operand types in theme() (line 1088 of \includes\theme.inc).

Unfortunately, this theme is no more supported, however I would like to find a workaround how fix this problem.