I have the same issue, but found a workaround.
First, I must mention that I can only have my add-on packages loaded on and pathed to a local server. If I try to path to the corporate server, Dynamo crashes on startup.
After logging into my system, and launching Dynamo for the first time, I have to either start a new blank dyn or open one that only utilizes packages loaded locally. I guess this sort of initializes the Dynamo pathing and from that point, I can then open any dyn from startup. This is only good while I am logged into my system. If I log out and log back in, I have to do the same scenario as described above all over again.
Yes, I agree BIMadmin, I also hope this gets fixed soon. Having to keep the packages updated on everyone’s computer across the corporate network is a pain.