I am not sure if mine is the same problem, but it may be.
I decided to test using older versions. While doing it I found that using any version on a local client and server worked ok. It fails when I am remote coming in through the firewall and adding recordings. (For example, submitting from my work)
I loaded the same version on the remote client and the server. 15.122, 15.130, 15.136 were all ok, then 15.142 failed.
I then decided to load a good version on the remote client (136) and keep the 'bad" version on the server, and it worked!
I have now gone back to running 15.171 on the server and 15.136 on my remote client that comes in via the FW. It submits ok.
Now, I never waited for some of these to actually record, but I assume my tests were valid in that I always checked the server side and saw the recordings in the "To Be Recorded" area.
Hopefully this helps!