Unable to write to Exception: Cannot open file - C:/Users/Public/Daybreak Game Company/Installed Games/EverQuest/EQGraphicsDX9.dll (13) - http://eq.patch.daybreakgames.com/patch/sha/eq/eq.sha.zs/91/a0c/32ede51c7fdf77098ffb516e0e6a620d382. The file may be in use or you may lack the necessary permissions to install.
Google: error message. I got numerous results. Check your anti virus progam - prob blocking something in this last update Is this test? Or TLP? TLP has been down but just came back up.
I had this exact same issue, but managed to fix it this morning. I have Avast antivirus, and I believe it was blocking the game from updating. I added the EverQuest folder, as well as LaunchPad.exe, to Avast's list of Exceptions (found in the settings menu) and then restarted my computer. The update worked just fine and I was able to load the game after that. Hope that helps!