Docker debug error

When I run Docker in debug mode: > docker daemon -D
I get a lot of errors like this: What do they mean and how do I have to solve them?

> INFO[0430] GET /containers/json?all=1                   
> DEBU[0430] Calling GET /containers/{name:.*}/json       
> INFO[0430] GET /containers/3b2d1c01fb3911c67e881c994340a250139d38f99c95221d2fddb64fbd18a8a1/json 
> ERRO[0430] Handler for GET /containers/{name:.*}/json returned error: Unknown device 3b2d1c01fb3911c67e881c994340a250139d38f99c95221d2fddb64fbd18a8a1 
> ERRO[0430] HTTP Error                                    err=Unknown device 3b2d1c01fb3911c67e881c994340a250139d38f99c95221d2fddb64fbd18a8a1 statusCode=500