PraetorianWolfie: The ScummVM log file could provide a reason for this error:
According to the ScummVM FAQ]ScummVM FAQ: On OS X the log file is '~/Library/Logs/scummvm.log'

Another thing to try could be to install a latest development build of ScummVM and run the game from that one, to see if that makes any difference.

Anton_Jensen: Respond: I tried deleting the log file. Nothing happened. If I download a new ScummVM emulator can I just play Blade Runner directly from that, because you know it comes as a packed deal.. ?

PraetorianWolfie: Sorry, I should clarify:
You should open the log file and read its contents because there's a chance the cause of the error or a specific error message anyway is recorded in that file.

Don't worry if you deleted it, it will recreate itself and it is re-written each time you run the Blade Runner game (or any ScummVM game)

The GOG release for Blade Runner runs ScummVM in the background. The ScummVM 2.1 stable version that was released back in October.

So, the game will run with a development build of ScummVM,but you'll have to add the game in that ScummVM installation (essentially you point ScummVM to the "Blade Runner" game directory that GOG has created for the game, and ScummVM will detect it and add it in its list so that you can launch it).

I can't guarantee that it will fix the crash error, but it might, or it may give us more information on the cause.

Anton_Jensen: Respond:

Log file says the following:
[2020-01-13 10:20:38] ScummVM 2.1.0 (Oct 12 2019 14:39:59)
[2020-01-13 10:20:38] Vorbis FLAC MP3 SEQ TiMidity RGB zLib MPEG2 FluidSynth Theora AAC A/52 FreeType2 JPEG PNG cloud (servers, local)
[2020-01-13 10:20:38] --- Log opened.
[2020-01-13 10:20:38] Using configuration file: configfile

I can't tell what is wrong from reading this...

PraetorianWolfie: Here's the log contents for me (on Windows with Blade Runner launching fine):
[2020-01-13 15:00:37] ScummVM 2.1.0 (Oct 5 2019 01:07:22)
[2020-01-13 15:00:37] Vorbis FLAC MP3 RGB zLib MPEG2 FluidSynth Theora AAC A/52 FreeType2 JPEG PNG cloud (servers, local)
[2020-01-13 15:00:37] --- Log opened.
[2020-01-13 15:00:37] Using configuration file: ..\project_nov.ini
[2020-01-13 15:00:37] Using pixel format: RGB888@4
[2020-01-13 15:00:38] Download SUBTITLES.MIX from ScummVM's website to enable subtitles
[2020-01-13 15:00:45] --- Log closed successfully.

In a Windows or a Linux setup, the "project_nov.ini" is the configuration file for Blade Runner and should be in the game folder that GOG created at installation. This could be different for some reason for MacOS systems, but to me it looks like an error. Maybe it's a permissions issue that make it fail access and read the proper configuration file?

tcrozat: I can confirm that on macOS the config file is named 'configfile' and this works for me.
Here is what I have in my log file after starting Blade Runner:

[2020-01-13 19:42:58] ScummVM 2.1.0 (Oct 12 2019 14:39:59)
[2020-01-13 19:42:58] Vorbis FLAC MP3 SEQ TiMidity RGB zLib MPEG2 FluidSynth Theora AAC A/52 FreeType2 JPEG PNG cloud (servers, local)
[2020-01-13 19:42:58] --- Log opened.
[2020-01-13 19:42:58] Using configuration file: configfile
[2020-01-13 19:43:17] WARNING: No path was provided. Assuming the data files are in the current directory!
[2020-01-13 19:43:17] Using pixel format: ARGB8888@4
[2020-01-13 19:43:18] Download SUBTITLES.MIX from ScummVM's website to enable subtitles
[2020-01-13 19:43:18] WARNING: numQueuedStreams: 0!
[2020-01-13 19:43:21] WARNING: numQueuedStreams: 0!
[2020-01-13 19:43:22] WARNING: numQueuedStreams: 0!
[2020-01-13 19:43:24] WARNING: numQueuedStreams: 0!
[2020-01-13 19:43:26] Blade Runner
[2020-01-13 19:43:26]
[2020-01-13 19:43:26] From the dark recesses of David Leary's imagination comes a game unlike any
[2020-01-13 19:43:26] other. Blade Runner immerses you in the underbelly of future Los Angeles. Right
[2020-01-13 19:43:26] from the start, the story pulls you in with graphic descriptions of a
[2020-01-13 19:43:26] grandmother doing the shimmy in her underwear, child molestation, brutal
[2020-01-13 19:43:26] cold-blooded slaying of innocent animals, vomiting on desks, staring at a
[2020-01-13 19:43:26] woman's ass, the list goes on. And when the game starts, the real fun begins -
[2020-01-13 19:43:26] shoot down-on-their-luck homeless people and toss them into a dumpster. Watch
[2020-01-13 19:43:26] with sadistic glee as a dog gets blown into chunky, bloody, bits by an
[2020-01-13 19:43:26] explosive, and even murder a shy little girl who loves you. If you think David
[2020-01-13 19:43:26] Leary is sick, and you like sick, this is THE game for you.
[2020-01-13 19:43:26]
[2020-01-13 19:43:26] JW: Don't forget the wasting of helpless mutated cripples in the underground.
[2020-01-13 19:43:26] It's such a beautiful thing!
[2020-01-13 19:43:26]
[2020-01-13 19:43:26] DL: Go ahead. Just keep beating that snarling pit bull...ignore the foam
[2020-01-13 19:43:26] around his jaws. There's room on the top shelf of my fridge for at least one
[2020-01-13 19:43:26] more head... - Psychotic Dave
[2020-01-13 19:43:26]
[2020-01-13 19:43:38] MG: Is David Leary a self-respecting human or is he powered by rechargeable
[2020-01-13 19:43:38] batteries?
[2020-01-13 19:43:38]
[2020-01-13 19:44:06] --- Log closed successfully.

You could try to start the application from the Terminal to see if that gives more information on what goes wrong. To do so:
1. Open the Terminal application
2. Drag & Drop Blade Runner.app on the Terminal window.
3. Erase the space at the end and add '/Contents/MacOS/GOGLauncher'. For example if Blade Runner.app is in your Applications directory you should now have /Applications/Blade\ Runner.app/Contents/MacOS/GOGLauncher in your Terminal window.
4. Press Enter (or Return). This will execute this command and should start the game.
5. After it crashes check the information that was printed in your Terminal window.

Anton_Jensen: Assertion failed: (p < _size), function setChar, file common/str.cpp, line 464.

tcrozat: This is the reason why it shuts down. The software tries to change a character in a string after the end of the string. But I have no idea why, or which parts of the software tries to do it. The `setChar` function is not used a lot, and I cannot see any part of the code where it is relevant for Blade Runner. So there is something really strange going on.

You could try to download a stable ScummVM version for macOS from https://www.scummvm.org/downloads and maybe that will work better than with the ScummVM version used by GOG in their release. After you start the ScummVM application you will need to add the Blade Runner game to it: click on Add Game and navigate to Blade Runner.app > Contents > Resources > game > game and select this folder. This should detect and add the game, Then you can start it.

Anton_Jensen: I acutually did this yesterday, not sure it was a 'stabel' tho. I just downloaded the recommended version under the download page. Did not work. The same thing happens.

PraetorianWolfie: There's a page with daily builds for ScummVM here:
https://buildbot.scummvm.org/builds.html

The left column is development builds and is updated daily with the latest fixes, but might be unstable for some (still worth a shot if all else fails). The right column is stable builds and it usually matches the latest published stable build, so it could be identical to what the GOG version has.

Btw, did you try some basic steps like:
* Verify the installation via GOG Galaxy's option
* Install the game in its default location, preferably one that has only Latin characters in the path (as opposed to any non-ASCII characters)
* If you have any other ScummVM supported games in GOG, do they run ok, or do they also have the same issue?
An example of such a ScummVM supported game in GOG would be Beneath a Steel Sky]Beneath a Steel Sky which is also free here.