Hi,
what you need is at least a hard disk image file with Windows 95, and Diablo 2 installed. I’m using a 512 MB c.img with Windows, and another 2 GB image as drive d:, which contains the game. The advantage is, that you can copy multiple 2 GB images to your phone, and mount them in different game profiles. So you can more or less install as many games as you want (as many images as your SD card can hold).

Anyway. In the game profile options, scroll down and check “Expert commands”. In expert settings, make sure you have set the correct mounting commands.

My mountings look like this:
@Echo Off
imgmount c /storage/extSdCard/Games/PC/Win95/c.img -t hdd -fs fat -size 512,63,16,520
imgmount d /storage/extSdCard/Games/PC/Win95/hdd-2gb.img -t hdd -fs fat -size 512,63,64,1023
boot -l c

The “boot -l c” command is mandatory to boot up Win95. Maybe adding this will already fix your issue.

If you’re unsure about the mounting, you can look up the correct hd mounting parameters for your hd image file size in the readme included in this package: https://www.mediafire.com/file/zpo4x975poe7co6/HDD_Images.zip/file
You can also use the empty image files if you wnat to add more games.

Check out this layout. It’s for Diablo 1, but I guess it can be easily adapted for Diablo 2.