Lecreateurlol63 You can also try to match resolution that the Batocera is expecting with Dolphin. In Dolphin somewhere in settings set it up to 1600/900 and in 'per system config' set it up to 1600/900 as well and try.
That is if I am reading this correctly:
2020-05-01 12:51:49 DEBUG (unixSettings.py:79):loadAll(): Looking for gamecube["Mario Kart - Double Dash !!.iso"]-renderer.* in /userdata/system/batocera.conf
2020-05-01 12:51:49 DEBUG (emulatorlauncher.py:72):main(): Settings: {'core': 'dolphin', 'showFPS': 'false', 'ratio': 'auto', 'uimode': 'Full', 'retroachievements.hardcore': u'0', 'retroachievements.verbose': u'0', 'smooth': True, 'retroachievements': u'0', 'bezel': 'default', 'video_threaded': False, 'retroachievements.screenshot': u'0', 'retroachievements.leaderboards': u'0', 'emulator': 'dolphin', 'rewind': False, 'forceNoBezel': False, 'videomode': 'default'}
2020-05-01 12:51:49 INFO (emulatorlauncher.py:74):main(): emulator: dolphin, core: dolphin
2020-05-01 12:51:49 INFO (emulatorlauncher.py:85):main(): current video mode: 1600x900
2020-05-01 12:51:49 INFO (emulatorlauncher.py:86):main(): wanted video mode: default
2020-05-01 12:51:49 ERROR (emulatorlauncher.py:229):<module>: configgen exception:
Traceback (most recent call last):
File "/usr/lib/python2.7/site-packages/configgen/emulatorlauncher.py", line 227, in <module>
exitcode = main(args)
File "/usr/lib/python2.7/site-packages/configgen/emulatorlauncher.py", line 90, in main
gameResolution = videoMode.getCurrentResolution()
File "/usr/lib/python2.7/site-packages/configgen/utils/videoMode.py", line 29, in getCurrentResolution
return { "width": int(vals[0]), "height": int(vals[1]) }
ValueError: invalid literal for int() with base 10: '900\n1600'