I suppose I have the same problem.
I had EB 2.4a plus Erkens temporary Strategicos mod for 2.4a installed on this computer and recently did a clean new install (because I wanted to check the "wrath of the norsemen" submod for "Last Kingdom" and got a couple errors there, eventually resulting in a completely re-installation of M2TW.
I have a Win10 system and have used my retail version of M2TW Gold for way over a decade now, usually with no problems at all. (I played EB II since the first version with this very M2TW gold version.)
So - M2TW completely removed (including registry cleanup), re-installed the game, re-downloaded EB 2.4a and istalled it, too. I followed Quintus' install instructions to the letter (or so I think). Installed Strategicos on top of it, as I did last time.
Started the game, chose Aedui, gathered the whole army and attacked the Arverni.
Some Averni FM comes to the rescue, I divert a couple units to hunt them down, start battle - CTD.
My first CTD in EB II in a very very long time.
I did the mentioned steps again to check if it was a single hiccup - but no, same crash at the same moment. Error message: "unspecified error".
Checked the log - LOTS of script errors!
'Okay', I thought, "you must have done something wrong with the installation.'
Removed everything again (registry cleanup, too), installed M2TW gold, installed EB2 - start, battle, crash. Script errors all over the place.
Puzzled, I started searching the net (and specifically this forum) for clues. Someone mentioned that M2TWEOP doesn't like non-Steam, so I registered my gold version with steam, removed everything again, downloaded the steam version, installed M2TW and EB2 - start, battle, crash. Script errors.
I am not sure what exactly I do wrong here since Quintus' installation guide is pretty straight-forward (thank you for this, by the way!).
I do a fresh install outside of C:/program files (using D:/steam, as I always do). I start a M2TW vanilla campaign before EB install.
I install the three mandatory Windows-programs, I use LAA.
I add the Steam-specific line in the starting options.
Interestingly - I can finish a battle (and get back to the campaign map) without crash if I play a faction like Rome, although f_rome is mentioned with script problems in the log, too.
EDIT: I stand corrected. I tested a couple other factions and ALL of them (except SPQR) crashed within the first battle. Some directly as the end of the deployment phase, some amidst the battle.
And when I - out of curiousity - tested ROME again, they crashed too.
I have added my log, and would appreciate any hints as to what exactly I did wrong with my install.