This way everything works.
Try opening the folder iGO_Avic with some file manager,to find the real name of extsd card.
I think it "/mnt/m_external_sd" from error message.
"The folder is missing or unfinished.
/mnt/m_external_sd/iGo_Avic/license.zip:/mnt/m_external_sd/iGo_Avic/license.zip: open failed: EACCES (Permission denied)"
Now if it is right to add to SYS.
for example: in my own sys is "/storage/extSDCard/iGO"
move "iGO_Avic" folder to extsd card
android/data/jp.pioneer.mbg.avicsync/files <- iGO_Avic
1.Rename or delete save folder
2.Go to settings -> app manager -> iGO and clean the cache.
3.Restart and try...