Hi!
If you're having problems while importing resources in AD/AP for iOS try the following:
1) Put the .afbrushes in your iCloud folder
2) Exit AD/AP
3) Open Files App
4) Tap the iCloud folder you put these in
5) Tap the .afbrushes file to make it properly synced (the tiny "cloud icon" must disappear)
6) Open AD and attempt the import again
This procedure should work fine.
Cheers!
Paolo