XF 2.1 The submitted message is too long to be processed. Please shorten it.

[xffutureuser]

Hello.
I am trying to create a thread in my forum and when clicking on "Post thread" I am getting this message: "The submitted message is too long to be processed. Please shorten it. "
Where is the setting to change it please? I have spent over one hour looking for it. Please let me know.
Thanks.

 

[Paul B]

Enter 'message length' in the ACP search.

 

[xffutureuser]

Thanks. that helped.