Can't launch Marvel vs. Capcom 2 (Retroarch / Flycast core) since 13.15

[midas]

I'm having an issue launcing Marvel vs. Capcom 2 for Sega Dreamcast. Other DC games launch fine, but I can't get MvC2 to launch. It's worked fine in the past.

In Task Manager I can see the retroarch.exe process start, then stop after a few seconds.

After poking around at it for the last hour I determined that I could load the game fine if I did it manually from within Retroarch, but it didn't load if I ran it from Launchbox. Other Dreamcast games had no issue loading from Launchbox using the same core. This led me to believe it was possibly something in Launchbox.

It's been awhile since I've played the game (7-8 months) and my Launchbox has been updated several times since then. On a hunch I decided to install a new instance of Launchbox in a different location, but using an older installer from around a time I know I'd successfully played it (13.12). I imported the game, let Launchbox install RetroArch, and copied the bios files over. The game launched fine.

I then updated Launchbox to 13.18 and after doing so the game no longer launched.

To see if the issue was caused by something during the update process, I then deleted the installation and did a fresh install of 13.18. The game would not launch.

I have a mini PC with 13.16 on it which I tried and it didn't work on that either. I did a fresh install of 13.16 on my desktop and it also would not launch.

Next, I deleted the 13.16 installation and installed 13.15. The game would not launch in this version either.

Finally I deleted the install and installed 13.14. The game launched normally.

So it would seem that the issue was introduced starting with 13.15. Is this a known issue? I was searching around and couldn't find anything about it, but I can repeat the problem on several different computers.

**EDIT** I can confirm that I re-ran the 13.14 setup to downgraded the 13.16 install on my mini PC and the game launched successfully again in 13.14.

 

Edited January 21 by midas

[SolarisSpell]

I haven't quite figured out what changed in version 13.14. When I detected the problem it was because one platform did work (I was playing SNES) and it wasn't until some time later when I tried to switch to Dragon Quest VI on Nintendo DS that I noticed it.

 

Although with the previous version it works, it would be nice if we could find out what has changed in the emulator calls in version 13.15 to be able to update again and not be permanently with the old version.

[midas]

I have confirmed issues launching various games on all of the systems I had that had been updated beyond 13.14. I see other folks with posts in the last 6 months having similar issues. Do we have any idea what the issue is? The only game I remember wasn't launching was Marvel vs. Capcom 2 for Dreamcast, so that's the barometer I was using for my testing. I can confirm it will not launch from Launchbox (using Retroarch) in any version after 13.14, but launches fine when loaded from within Retroarch itself.

To confirm my testing method:

• I would install a fresh copy of LaunchBox in a new folder.
• I would import the Marvel vs. Capcom 2 Dreamcast .chd file, telling it to use Retroarch and allowing it to install it, using flycast-libretro core (I also had tried downloading Retroarch from their site and instructing LaunchBox to use that, but it didn't make a difference).
• Once imported I tried to launch the game. The retroarch.exe process showed up in Task Manager, then after a few seconds disappeared.
• I launched Retroarch directly, loaded the flycast-libretro core, then loaded the Marvel vs. Capcom 2 .chd and it worked fine.

I repeated those for every version from 13.14 through 13.18 and from 13.15 onward I had the same problem--13.14 is the last one that worked.

Edited January 21 by midas

[midas]

I think I've found the problem: Starting in Launchbox 13.15 something appears to have changed with how it passes characters in a file path to the emulator.

In all of my testing I'd either just copied the folder with the MvC2 CHD over to the new installation, or--when trying CHDs from different sources--replaced the file that was there (even changing its name but not its folder).

In my fresh 13.20 install however, I'd only placed the CHD file in the Sega Dreamcast folder rather than having it in a subfolder for the game.

In continuing testing this morning I happened to notice what appeared to be double spaces before (USA) in the folder name. I removed the extra space, updated the game's launch path, and the game launched fine.

So it looks like although Launchbox can see the extra space (it's visible when viewing the path in the launch location) it's not passing that on to Retroarch when telling it to launch the game. This is shown in the log console I posted before, where it said it couldn't read the attributes of the file--of course it couldn't, because the path it was given didn't have the extra space in the folder name.

To further test this, I went to a game I've launched a hundred times: Castlevania - Symphony of the Night on PS1.

• I launched the game successfully, then exited.
• I located the folder with the BIN/CUE and added an extra space to it.
• In Launchbox I edited the metadata, went to the Launching section and browsed to the new location of the .CUE file.
• I confirmed that the folder now showed the extra space.
  
  
   
• I saved the settings and tried to launch the game. It did not launch.
• I renamed the folder to remove the extra space, re-browsed to/selected the .CUE and saved the settings.
• I successfully launched the game.