I have nougat running on a moto g and have my sd card setup as local storage. With this setup pocket gets installed on the sd card by default. When I try to load my dropbox sync however i get a little message saying 'unable to save' and the load just runs forever without making any apparent progress.
I worked around the problem by going into settings->applications and moving pocket into internal storage.
I can't thank you enough. It worked for me with Marshmallow (6.0.1) on a Moto G 3rd Gen. I didn't get the problem on a Nexus 7 2nd Gen also on 6.0.1 but then it doesn't have an SD card capability.
Thank you again (can you tell how relieved I am at not having to change to another password vault)