Same happend to me with Mame4all-pi, i did not have permission to save the config to opt/retropie…… etc etc.
What i found was to do this in terminal: sudo chmod 777 (the map you need permission for) then go back mame4all-pi and you can map your buttons and save the config.
The same thing works with retroarch.
you will need root acces to cfg the most emulators.
I was a bit reluctant to propose this workaround as I haven’t tested it thoroughly but given the increasing number of posts about it here we go!
Launch a command line and issue the following command:
$ sudo chown -R pi:pi /opt/retropie/
You should end up with:
$ ls -la /opt/retropie/
drwxr-xr-x 6 pi pi 4096 Jul 1 22:40 .
drwxr-xr-x 5 root root 4096 Jul 1 21:34 ..
drwxr-xr-x 17 pi pi 4096 Jul 1 21:47 configs
drwxr-xr-x 13 pi pi 4096 Jul 1 21:42 emulatorcores
drwxr-xr-x 24 pi pi 4096 Jul 1 22:30 emulators
drwxr-xr-x 5 pi pi 4096 Jul 1 22:31 supplementary
Let me know if this does improve your situation.
As a windows user and linux starter i like to change my retroarch files inside a gui. To do that i type “sudo su” in shell to get root acces and afterwards “startx” to enter rasbian gui then i can open the file via leaf and save changes. After I’m done i just reboot to loose root acess again…