- root your Kindle Fire HD 2013
- Download and install ES File Explorer from amazon AppStore (its free)
- Start ES File Explorer and enable Root Explorer
- Browse to "/data/securedStorageLocation/dtcp/"
- Marke the "adunits" folder
- Go to "more" and "settings"
- Remove the permissions from "rwx --- ---" to "--- --- ---"
- (Optional) Remove all folders in the adunits folder
Sorry for my bad english.