Problem seems to be solved.
I started a new career, under the name of "Albert Keller." "Albert the Kraut" was a kid of German heritage who lived in our apartment building when I was a kid growing up in Toronto in the 1970s. He was a problem child, liked to knick things from stores and even from other kids at school. He even had the nerve to set fire to a gas station garbage dumpster and blame my younger brother for it, even when I saw him coming out from behind the dumpster just before the fire. I saved my little brother from getting his backside tanned by Dad when I told my father I saw Albert lurking behind the gas station just before the fire. His mother was crazily after my father, who was our building's superintendent. She would shamelessly strip off and parade around naked when my Dad was hauling ashcans from our coal-fired heating system in the alleyway outside her apartment. Dad got a kick out of it but never took her up on the offer.
Ahem.. back to the game...
What I did this time was start the game not via Commander but by the LSH starter icon. Then I created "Albert Keller" and did the Erpro patrol. I did not sink anything, as I do not wish peacetime training kills to show up in my log. Returned to Stralsund in the evening of August 2nd, 1939. Saved the game while in-base, dished out the gongs awarded in-game, then applied for the transfer to Wilhelmshaven. This time it worked, no null base message. I saved and exited game. Then I fired up Commander and I see Albert Keller and his status in Wilhelmshaven before patrol 2. I can now start the game using Commander, enable its options and tinker with my boat and crew, without having to worry about that first patrol bug that fails to credit kills.
Anyhow, seeing as I had such problems getting my first career in LSH2015 going, I decided to name my problematic first career after the first problematic kid I grew up with. Albert, prost, wherever you are!
And
to Berbster and all who offered help. Now I must have a lunch of unshaved pig and tea and get out to sea, kameraden, for a peacetime patrol to the west of England. Do you think that old cigar chomper von Churchill will start a war?