it looks like its the same as Delta 1.28.2 Desktop Nach Update keine Funktion - #15 by Secretuser
set "lastAccount" in config.json in the data directory to “1” or delete that line, that should quick fix it.
I made a pr to fix this in the upcoming test version: fix account migration crash by Simon-Laux · Pull Request #2738 · deltachat/deltachat-desktop · GitHub