Locus Map 4 (Gold) and Android 5.1.1

[JonRei]

I have a Samsung Tab running Andoid 5.1.1. (I know it is old, but it is the device I use for navigation i the boat) and Locus Map 4 Gold. However, my prime storage is filled up and I had to move Locus to the external storage card (incl all the Locus libraries). When trying to download maps from Locus Store (Statkart Sailing) I get the error code 12547, indicating write protected storage card, which is not true. I know that at some time in Andoid development a special permission was introduced to let an App write to external storage and it seems like Locus is not requesting this permission.
Does this sound familiar, and are there any tips how to solve?

[JonRei]

Problem solved by rooting the device and update /permissions/platform.xml as described here..
https://www.dtechy.com/unlock-external-sd-card-write-permission-for-all-apps-in-android-lollipop-kitkat/