Uncaught TypeError: Unsupported operand types

[Peter Monkeymedia]

Hello,

I am using revive ads, when I try to display ads via iframe, the next error appears:

Fatal error: Uncaught TypeError: Unsupported operand types: string + array in /data/b/2/b2d9ac70-6b9b-45c3-9333-85efbc0f13f4/mmproject2.sk/web/ads/www/delivery/afr.php:3999 Stack trace: #0 /data/b/2/b2d9ac70-6b9b-45c3-9333-85efbc0f13f4/mmproject2.sk/web/ads/www/delivery/afr.php(3810): _adSelectZone(1, Array, '', true) #1 /data/b/2/b2d9ac70-6b9b-45c3-9333-85efbc0f13f4/mmproject2.sk/web/ads/www/delivery/afr.php(4470): MAX_adSelect('zone:1', '', '', '', 0, 'UTF-8', Array, true, '', 'https://www.mmp...', NULL) #2 {main} thrown in /data/b/2/b2d9ac70-6b9b-45c3-9333-85efbc0f13f4/mmproject2.sk/web/ads/www/delivery/afr.php on line 3999

My php version is 7.4