I have also tried all of the offered solutions and none of them have worked. I even went through the whole video and none of it worked. Quite confused now
Have tried every solution on this thread and nothing has worked. Still stuck on pumping sim once and am just getting annoyed. Got exited for this game and am quite dissapointed.
I have the same problem and deleting the PD launcher did not work. Nor did launching from KSP2_x64.exe. I am just stuck on pumping sim once. Got exited for this game and am hoping for a solution soon