I was having the same issue. After trying permissions, uninstalling and re-intsalling, and everything else nothing worked.

I checked the processes on my Mac and opened the dynamiclinkmediaserver process and clicked on the "Open Files and Ports" section, and I saw that it was indicating that it's origin is "Applications/Adobe Photoshop CC 2018/Adobe Photoshop CC 2018.app/Contents/Required/DynamicLinkMediaServer/dynamiclinkmediaserver.app/Contents/MacOS/dynamiclinkmediaserver".

I opened a finder folder and explored all the way to the "MacOS" folder on the previous path and clicked the dynamiclinkmediaserver exec. It opened a window that stated there was an error reading a file in the following path: User(usually your name)/Library/Preferences/Adobe/dynamiclinkmediaserver/10.0.0/Trace Database.txt

When I opened such file with the text edit app I noticed it was blank, empty. Under the folder "dynamiclinkmediaserver" I saw another folder named 7.0.0 and it has a similar file named Trace Database.txt and it contains the following text:

IFDR      1       5

dynamiclinkmediaserver    1      5

processcoordination          1      5

I copied the same text to the .txt file in the 10.0.0 folder and....THE PROBLEM IS SOLVED.

I don't know if the same text would work, I would suggest to follow the same paths to see if the problem is the same, and see if you also have another folder like 7.0.0 whit a similar .txt file that you can copy, but this worked for me. Good luck