I have the same error.
While it´s fixed, play from "DiabloII.exe" in your diablo2 folder. Im playing online whit it.

At this moment im testing an apocalypse fire witch. Reached 14500 damage with minefield + blazing armament. Need to make futher tests but, at level 140 cleaned, using only apocalypse, fautz in less than 10 minutes. Mothe than 330% FSD and 185 fire pierce. Problems: high mana dependance (higher curre...

https://ibb.co/4Mt5ch1
RD sorc.
Only gear, no shockets filled.