PHP Fatal Error with theme Impreza

I use the theme Impreza on my wordpress with php 7.3. Since the last update, some pages of the site have crashed. The backend and pages with content prior to the update work flawlessly, while pages updated with new content report error 500.
The error can only be resolved by deactivating one of the two conflicting plugins: UpSolution Core or Download Manager. Is there any way to find a solution to continue using both plugins?

This is the log:
PHP Fatal error: Allowed memory size of 268435456 bytes exhausted (tried to allocate 157298688 bytes) in /var/wwwc/movimentofac/wp-content/plugins/us-core/templates/single.php on line 46
PHP Fatal error: Allowed memory size of 268435456 bytes exhausted (tried to allocate 157278712 bytes) in /var/wwwc/movimentofac/wp-includes/functions.php on line 4344
PHP Fatal error: Unknown: Cannot use output buffering in output buffering display handlers in Unknown on line 0