Save files no longer available to load after blowing up a large rocket

[Markrs240B]

• KSP Version - KSP 2
• Operating System and version - Windows 10 build 19044.2604
• CPU and GPU models - Ryzen 5 5600G, Nvidia 4070ti, 128GB ram
• Description of the bug.  - After successfully launching a very large rocket configured as an airplane (a mk3-5 cockpit with a "Wayfarer" crew module and enough boosters to possibly fly like a plane into orbit), the vehicle blew up on staging and when I reverted to the VAB as a joke I launched from the boat launch, where it collapsed under its own weight and blew up. When I reverted to VAB to try flying from the runway again the launch button would no longer work. The menu for saving workspaces no longer showed previous saves, and the load menu showed stock items only. When I restarted the game only some autosaves were available to load, but the launch button still did not work. Further, I am unable to save anything.
• Steps to Replicate - At one point some combination of restarting the game, then visiting all the different parts of the KSC got me back my access to saves. This may have been triggered by going to training, because it still had tracked what training missions I'd done. After getting access to my saves again, I noticed the very large vehicle I was working on was still missing. I built a second very large vehicle similar to the first and it blew up on the runway, collapsed under its own weight without moving. I reverted back to the VAB to add more struts and wheels, and again my saves no longer show up at all.
• Fixes / Workarounds - None
• A list of ALL mods. - None
• Other Notes / Screenshots / Log Files (if possible..)

I'm not sure if this matters, but because I was in such a rush to get into the game I forgot to name my agency, so the name is "Default".

The images below are of the vehicles I was trying to launch. The first one was actually making good progress, but the SRB's under the wing kept blowing us up at stage separation. This is the one that we 'launched' at the boat launch as a joke.

Below that are pictures of the first plane actually moving down the runway with beautiful rocket plumes, and the second plane that I built after the workspace for the first disappeared.