Can't download certain app on Google Play (Error -18)

[Soapsz]

I cannot download a certain app
Namely, "Unity-Chan Action Shooting".
I "uninstalled" it once, as its files suddenly got stuck in the SD card, then none at all.
Any attempt to redownload it gives me Error -18
I cannot edit anything in "My Files" with or without a computer.
Downloading other games are fine however.
Not sure if this is needed,
Samsung Note 2

 

[dpham00]

Try to clear cache and app data on the Google play store app

 

[Soapsz]

Problem persists with Error -18

 

[Soapsz]

I thank you for your help, dpham00.
I have solved it by reformatting my almost empty SD card.
Apparently, app remnants were in the SD card, and uninstallation was not possible as the root file could not be found by the system or something like that I may never understand.


But in the end, I think I may never know what error -18 is.

Google should really explain what every code is rather than just put a blind code there.