I maybe found the reason why rcb doesnt start dolphin..
I compared the logparts of ppsspp and dolphin and here are the differences:
PPSSPP:
2019-03-05 19:08:51.595 T:139917485143808 DEBUG: RCB_INFO launcher.buildCmd
2019-03-05 19:08:51.595 T:139917485143808 DEBUG: RCB_INFO emuCommandLine: /storage/.kodi/userdata/addon_data/script.games.rom.collection.browser/scriptfiles/PPSSPP.start
2019-03-05 19:08:51.595 T:139917485143808 DEBUG: RCB_INFO preCmdLine:
2019-03-05 19:08:51.595 T:139917485143808 DEBUG: RCB_INFO postCmdLine:
2019-03-05 19:08:51.595 T:139917485143808 DEBUG: RCB_INFO Getting Multiple Disc Parameter
2019-03-05 19:08:51.595 T:139917485143808 DEBUG: RCB_INFO emuParams: "%ROM%"
2019-03-05 19:08:51.595 T:139917485143808 DEBUG: RCB_INFO rom: /var/media/SPIELE/PSP/Roms/FlatOut - Head On/FlatOut - Head On [D][ULES-00969].cso
2019-03-05 19:08:51.596 T:139917485143808 DEBUG: RCB_INFO No precmd created.
2019-03-05 19:08:51.596 T:139917485143808 DEBUG: RCB_INFO No postcmd created.
2019-03-05 19:08:51.602 T:139917485143808 DEBUG: RCB_INFO cmd: "/storage/.kodi/userdata/addon_data/script.games.rom.collection.browser/scriptfiles/PPSSPP.start" "/var/media/SPIELE/PSP/Roms/FlatOut - Head On/FlatOut - Head On [D][ULES-00969].cso"
2019-03-05 19:08:51.602 T:139917485143808 DEBUG: RCB_INFO precmd:
2019-03-05 19:08:51.602 T:139917485143808 DEBUG: RCB_INFO postcmd:
2019-03-05 19:08:51.602 T:139917485143808 DEBUG: RCB_INFO launchEmu on non-xbox
2019-03-05 19:08:51.602 T:139917485143808 DEBUG: RCB_INFO screenMode: HDMI1: 1920x1080 @ 60.00Hz
2019-03-05 19:08:51.602 T:139917485143808 DEBUG: RCB_INFO launch emu
2019-03-05 19:08:51.702 T:139917485143808 DEBUG: RCB_INFO: onAction: 7
2019-03-05 19:08:52.603 T:139917485143808 DEBUG: RCB_INFO __executeCommand
2019-03-05 19:08:52.604 T:139917485143808 DEBUG: RCB_INFO execute command with os.system
2019-03-05 19:08:52.715 T:139917476751104 DEBUG: Thread LanguageInvoker start, auto delete: false
2019-03-05 19:08:52.715 T:139917476751104 INFO: initializing python engine.
2019-03-05 19:08:52.715 T:139917476751104 DEBUG: CPythonInvoker(16, /usr/bin/audio-suspend.py): start processing
2019-03-05 19:08:59.266 T:139919213188864 DEBUG: BUTTON [ 2 ] on "Gasia Co.,Ltd PS(R) Gamepad" pressed
2019-03-05 19:08:59.444 T:139919213188864 DEBUG: BUTTON [ 2 ] on "Gasia Co.,Ltd PS(R) Gamepad" released
2019-03-05 19:09:08.062 T:139919213188864 DEBUG: BUTTON [ 9 ] on "Gasia Co.,Ltd PS(R) Gamepad" pressed
2019-03-05 19:09:08.240 T:139919213188864 DEBUG: BUTTON [ 9 ] on "Gasia Co.,Ltd PS(R) Gamepad" released
2019-03-05 19:09:17.208 T:139919565518592 DEBUG: Thread JobWorker 139919565518592 terminating (autodelete)
2019-03-05 19:09:17.208 T:139919857952512 DEBUG: Thread JobWorker 139919857952512 terminating (autodelete)
2019-03-05 19:09:17.208 T:139918214948608 DEBUG: Thread JobWorker 139918214948608 terminating (autodelete)
2019-03-05 19:09:17.217 T:139919557125888 DEBUG: Thread JobWorker 139919557125888 terminating (autodelete)
2019-03-05 19:09:17.646 T:139919213188864 DEBUG: BUTTON [ 10 ] on "Gasia Co.,Ltd PS(R) Gamepad" pressed
2019-03-05 19:09:17.809 T:139919213188864 DEBUG: BUTTON [ 10 ] on "Gasia Co.,Ltd PS(R) Gamepad" released
2019-03-05 19:09:20.420 T:139919213188864 DEBUG: BUTTON [ 2 ] on "Gasia Co.,Ltd PS(R) Gamepad" pressed
2019-03-05 19:09:20.534 T:139919213188864 DEBUG: BUTTON [ 2 ] on "Gasia Co.,Ltd PS(R) Gamepad" released
2019-03-05 19:09:25.066 T:139919213188864 DEBUG: BUTTON [ 2 ] on "Gasia Co.,Ltd PS(R) Gamepad" pressed
2019-03-05 19:09:25.181 T:139919213188864 DEBUG: BUTTON [ 2 ] on "Gasia Co.,Ltd PS(R) Gamepad" released
2019-03-05 19:09:25.583 T:139917485143808 DEBUG: RCB_INFO launch emu done
2019-03-05 19:09:25.588 T:139919557125888 DEBUG: Thread LanguageInvoker start, auto delete: false
2019-03-05 19:09:25.588 T:139919557125888 INFO: initializing python engine.
2019-03-05 19:09:25.588 T:139919557125888 DEBUG: CPythonInvoker(17, /usr/bin/audio-resume.py): start processing
2019-03-05 19:09:25.683 T:139917485143808 DEBUG: RCB_INFO: onAction: 122
2019-03-05 19:09:25.683 T:139917485143808 DEBUG: RCB_INFO: onAction: ACTION_CANCEL_DIALOG
2019-03-05 19:09:25.683 T:139917485143808 DEBUG: RCB_INFO: exit
2019-03-05 19:09:25.683 T:139917485143808 DEBUG: RCB_INFO: Begin saveViewState
2019-03-05 19:09:25.689 T:139917485143808 DEBUG: RCB_INFO: Begin saveViewMode
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dolphin:
2019-03-05 19:10:01.520 T:139919557125888 DEBUG: RCB_INFO launcher.buildCmd
2019-03-05 19:10:01.520 T:139919557125888 DEBUG: RCB_INFO emuCommandLine: /storage/.kodi/userdata/addon_data/script.games.rom.collection.browser/scriptfiles/dolphin.start
2019-03-05 19:10:01.520 T:139919557125888 DEBUG: RCB_INFO preCmdLine:
2019-03-05 19:10:01.520 T:139919557125888 DEBUG: RCB_INFO postCmdLine:
2019-03-05 19:10:01.520 T:139919557125888 DEBUG: RCB_INFO Getting Multiple Disc Parameter
2019-03-05 19:10:01.523 T:139919557125888 ERROR: EXCEPTION Thrown (PythonToCppException) : -->Python callback/script returned the following error<--
- NOTE: IGNORING THIS CAN LEAD TO MEMORY LEAKS!
Error Type: <type 'exceptions.UnicodeEncodeError'>
Error Contents: 'ascii' codec can't encode character u'\xa0' in position 21: ordinal not in range(128)
Traceback (most recent call last):
File "/storage/.kodi/addons/script.games.rom.collection.browser/resources/lib/gui.py", line 365, in onClick
self.launchEmu()
File "/storage/.kodi/addons/script.games.rom.collection.browser/resources/lib/gui.py", line 1017, in launchEmu
launcher.launchEmu(self.gdb, self, gameId, self.config, selectedGame)
File "/storage/.kodi/addons/script.games.rom.collection.browser/resources/lib/launcher.py", line 47, in launchEmu
cmd, precmd, postcmd, roms = self._buildCmd(gui, filenameRows, gameRow, False)
File "/storage/.kodi/addons/script.games.rom.collection.browser/resources/lib/launcher.py", line 145, in _buildCmd
match = re.search(self.romCollection.diskPrefix.lower(), str(gamename).lower())
UnicodeEncodeError: 'ascii' codec can't encode character u'\xa0' in position 21: ordinal not in range(128)
-->End of Python script error report<--
2019-03-05 19:10:01.523 T:139919557125888 DEBUG: RCB_INFO: onAction: 7
2019-03-05 19:10:19.589 T:139920001240384 DEBUG: Keyboard: scancode: 0x09, sym: 0x001b, unicode: 0x001b, modifier: 0x0
2019-03-05 19:10:19.723 T:139920001240384 DEBUG: Keyboard: scancode: 0x09, sym: 0x001b, unicode: 0x0000, modifier: 0x0
2019-03-05 19:10:19.723 T:139920001240384 DEBUG: HandleKey: escape (0xf01b) pressed, action is PreviousMenu
2019-03-05 19:10:19.723 T:139919557125888 DEBUG: RCB_INFO: onAction: 10
2019-03-05 19:10:19.723 T:139919557125888 DEBUG: RCB_INFO: onAction: ACTION_CANCEL_DIALOG
2019-03-05 19:10:19.723 T:139919557125888 DEBUG: RCB_INFO: exit
2019-03-05 19:10:19.723 T:139919557125888 DEBUG: RCB_INFO: Begin saveViewState
2019-03-05 19:10:19.742 T:139919557125888 DEBUG: RCB_INFO: Begin saveViewMode
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Don't know what this means though. However I attached the files that are named in the error note. Maybe you want to check it..