For the file where nothing can be moved, did you create the file or was it given to you? Did it used to move and now it won't? We need a little more info to help you solve it. Tell us more about the scenario.
Have you tried right-clicking in a viewport and clicking 'Unfreeze All' from the quad menu? It's possible that everything in the file is frozen.
For the 'spacebar' issue it's possible that the key is not connected to 'freeze' anymore. Try using the right-click method I mention above to lock (freeze in Maxspeak) and unlock items. You can also look in the Max 'Help' file to see how to set keystrokes and go make sure if 'Freeze' is assigned to the 'spacebar' or not.
Finally, there is a button in the UI called "Keyboard Shortcut Override Toggle." It's normally next to the 'Snaps' toggle. Click that to change its current state and see if the 'spacebar' will now freeze and unfreeze.
If all of that fails, upload the file and I'll have a look at it.
Rob Holmes

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3ds Max (2023-2026), V-Ray 7, Ryzen 9 9950X3D Processor, DDR5 128MB, Gigabyte Aorus X870E Master motherboard, Sabrent Rocket NVMe Gen5 M.2 drives, NVidia RTX 4090, Space Pilot Pro, Windows 11 Pro x64, Tri-Monitor, Cintiq 13HD, Windows 11 x64
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