This is a longstanding bug relating to the game and the Apple OS.
Here is the solution/work around.
Press Escape to get to the Game Menu
Top left go to - Video
Top right go to - Texture quality
If you have this setting on High, change it to - Low
If you have it on Low, change it to - High
Click the bottom middle button - Accept
A pop up menu will appear saying
“WARNING! Accept new options? Reverting in 10 sec.”
Click - Cancel
That is the first part which forces the video to reset and will allow you to open your and see your Inventory items instantly. Do this step immediately when starting a new game. FYI: When playing in a group I make a habit of doing this immediately at the start every new game while people are milling about.
You will see immediate results after this step
The second part is maintenance to make D3 run more efficiently on your computer. Every time Diablo updates the game, the new update gets placed to different parts of your computer. Over time the Diablo program and data can become fragmented all over your computer. Diablo must then search for all these random pieces of D3 game. This slows down the whole game.
This is the second step
Quit Diablo AND [Battle.net](http://Battle.net)
Check to see that both Applications are closed and press ⌘ + Tab
Press ⌘ + Shift - A to open the Application folder
(Keep this folder open on your desktop)
Open the Folder - Diablo III
Select the Folder - Data
(This has four folders within: config, data, indices, patch)
Trash the Data folder, and then empty Trash
Restart your Mac
(The Applications folder>Diablo III folder will be on your desktop. If it isn’t repeat:
⌘ + Shift - A to open the Application folder
Launch [Battle.net](http://Battle.net)
At the top of the Menu click the DIII icon
At the bottom left of the Menu click Play
(Within the Diablo III folder you will a new Data folder and the four folders).
Sometimes the button will change to “Playing Now” because the update was quick.
Sometimes the button will change to “Updating” and give you a meg countdown of how much time is left with the upload. When you see the updating countdown bar say the game is “playable” WAIT until the entire update is complete. If you launch and play the game while it is updating, this will cause the game to be fragmented.
DIII will launch and you can play the game
Do this second step when you have the time. Thereafter you only have to do it after a new patch is launched.
One final housekeeping task I do is:
Within the Diablo III folder right click the Data folder to color it green. This way when the next update comes out I can do this step without trying to remember the folder to trash.