Hey Guys, i am new in this forum and hope that some one of you have a idea to help me. First of all, my englisch is not the best. I´m from germany but i will try my best to write as good as possible. Now lets get to my problem. I have a 27" iMac (late 2013) and i use 2 external Monitors. One is a 27" Cinema Display and the other one is a 27" Thunderbolt Display. The hole setup works perfectly. But now i have added a Wacom Cintiq 13" HD to system. If i connect this one via HDMI to Thunderbolt adapter to the Thunderbolt display i get the info that it won´t work. So i called Apple and the support says that the iMac only allows 2 external Monitors. So i bought a HDMI to USB3.0 Adapter from CableMatters and it works. But i have some issues like a black document screen in photoshop if the image is a lot bigger. Thats why i thought to ask you. Does anyone knows a tool, plugin, script or what ever to get the 4th monitor to work if it is connected normally through hdmi to thunderbolt? I would say that it is only a setting in the system that tells the imac "don´t let this work". What are your thoughts about this, any ideas??? Thanks for reading my post.