I'm getting the same result on Temporal Ambassador with the Map Transfer Failed issue when prompted to board the Enterprise-C (playing on Xbox One as a Fed-aligned Romulan). I ended up skipping that mission and was able to play through the rest of the episode with no apparent problems, so I'm wondering if this is limited…
I'm having the exact same problem. Tried with varied amounts of items, varied types of items, different characters, etc. and all I can do is send text emails. My mailbox is completely empty and I'm still having problems with this. Hope this is not a long term issue as I just started this back up again and I'm working on…