Bug making The Excavation at Hob's Barrow unplayable

[Nono69]

Hello everybody. I'm new here, so please forgive me if I don't do this request properly. Also, I'm French, so my English is probably not perfect.
I need help : I bought the game "The Excavation at Hob's Barrow" on GOG, and extracted its files using inoextract. Then I started playing it with ScummVM.
At first everything went well, but then I encountered what looks like a bug, wich makes the game unplayable : At the begining of the game, when I enter the inn and ask the inkeeper for a room, all I'm getting from him is a small black box with no dialog in it to choose (see attachment). From there I can't do anything except close the game.
Just to be sure, I installed the game on my PC through the installer, and the problem doesn't appear, the game works just fine, I can choose the dialog and go on with the game.
Then, just in case I did something wrong in the first place, I deleted the game from ScummVM, extracted the files again, and added them again to ScummVM, and the bug appeared again.
So, what should I do ? I checked the compatibility page, the game is supposed to work with ScummVM, so I'm kind of lost here...
I know that the obvious solution is to play the game on my computer with a regular installation, but I'd like to play it on ScummVM because it allows me to play on my phone when I'm commuting to work, on my computer when I get home, and then on an old tablet when I go to bed.
Any help will be appreciated !

[tag2015]

Hi, what version of ScummVM are you using? And what platform? Was the game properly detected or did ScummVM report it as an unknown variant?
I tested the game just now on Win10 (I tried scummvm 2.9.0 and my build), starting from the beginning, and I could proceed after that part just fine.

[Nono69]

I'm using ScummVM 2.9.0, on Windows 10. And yes, the game was perfectly detected, no problem whatsoever. I really can't figure this out.

[Praetorian]

Just to be sure, I installed the game on my PC through the installer, and the problem doesn't appear, the game works just fine, I can choose the dialog and go on with the game.

On this particular step, after properly installing the game on your PC using its installer and not innoextract, did you try adding the game to ScummVM 2.9.0? Is the bug still there in this case?

[Nono69]

I can"t understand why, but it worked. Thanks a lot !

[Nono69]

AAARGH ! No, problem un-solved ! This morning it worked, I was happy, I closed the game and went on with my life. Two hours later, I run the game again, and the problem's back with the next innkeeper dialog !!!
At this point I suppose there's a problem with my hardware. I can't think of any other explanation.
So I guess I'll be playing the game on my computer, through a regular installation...