Hello,
FIRSTLY please ensure you have the latest version of ROP installed.
The PHP Fatal error: Cannot redeclare tgmpa_load_bulk_installer() (previously declared in /var/www/vhosts/socialblabla.com/httpdocs/wp-content/plugins/tweet-old-post-pro/inc/lib/dependencies/class-tgm-plugin-activation.php:3154) in /var/www/vhosts/socialblabla.com/httpdocs/wp-content/themes/socialblabla/includes/wp_booster/external/class-tgm-plugin-activation.php on line 1694 error is caused because your theme developer has not updated their TGMPA file to the latest version.
The error is saying that the function is already declared because it's being declared in ROP and your theme, in the latest version of ROP we have updated the TGMPA to the latest one so it checks if the function is already declared.
Please log into your website via FTP and rename the folder of your "socialblabla" theme then log back into the website, you could then go back and undo the rename.
Then let your theme developer know they need to update TGMPA.
Best regards,
Uriahs