The problem is on Horizon's usa installation for me.., the gray is present on texture missing, please try to deactivate kord from scenery library, and test Horizon's Usa.
Thanks for remind me.
I found out the issue on texture,
Horizon's sesonal texture have to be instilled as FS showing season
and make sure have Horizon's sesonal texture have to be instilled
Than It will be compatibility with FSDreamteam Ohare senercy
Thank you for help