stdClass could not be converted to string in ObjectSerializer

[basdog22]

Hello. I get an error of stdClass could not be converted to string whenever i try to create a campaign from the API.

The campaign gets created at Moosend successfully though.

local.ERROR: Object of class stdClass could not be converted to string {"exception":"[object] (ErrorException(code: 0): Object of class stdClass could not be converted to string at /var/www/sites/demosite/app/Tools/Moosend/lib/ObjectSerializer.php:264)

The campaign gets created at Moosend successfully though.