Start up crash with a grey screen

[Boubou-1741]

Just a guess… are you using a Razer mouse and/or keyboard ?
If so, check this topic:

Known Technical Support Issues - [Updated June 21, 2020!]

Gray or white flash before Crashes Due to Razer Chroma Software We’ve received a number of recent reports of crashes with past builds of Razer Chroma SDK. Razer has been working on the problem for a while, and it appears to have been fixed with Razer Synapse 3. Below are steps to resolve the issue. Diablo III Workaround Go to the Documents folder. Select the Diablo III folder. Open the D3prefs.txt file using Notepad. Add or Edit the following line. The value should be 1, like so: DisableCh…

If you are not using a Razer mouse/keyboard, then you should provide your DxDiag report; see Blizzard Support - Obtaining System Files for the procedures on how to create it.

Once you have created the report, post it in your reply between two lines of 3 tildes, as in:

~~~
   paste DxDiag report here
~~~