problem while using Boot Camp Assistant

AirdiRiaMengoli:Library ritamengol$ sudo fsck_apfs -n -l /dev/rdisk1

Password:

** Checking the container superblock.

** Checking the EFI jumpstart record.

** Checking the space manager.

** Checking the space manager free queue trees.

** Checking the object map.

** Checking volume.

** Checking the APFS volume superblock.

** The volume Macintosh HD was formatted by hfs_convert (748.67.14) and last modified by apfs_kext (945.230.6).

** Checking the object map.

** Checking the snapshot metadata tree.

** Checking the snapshot metadata.

** Checking snapshot 1 of 4.

** Checking snapshot 2 of 4.

** Checking snapshot 3 of 4.

** Checking snapshot 4 of 4.

** Checking the extent ref tree.

** Checking the fsroot tree.

** Checking volume.

** Checking the APFS volume superblock.

** The volume Preboot was formatted by newfs_apfs (748.67.14) and last modified by apfs_kext (945.230.6).

** Checking the object map.

** Checking the snapshot metadata tree.

** Checking the snapshot metadata.

** Checking the extent ref tree.

** Checking the fsroot tree.

** Checking volume.

** Checking the APFS volume superblock.

** The volume Recovery was formatted by newfs_apfs (748.67.14) and last modified by apfs_kext (945.230.6).

** Checking the object map.

** Checking the snapshot metadata tree.

** Checking the snapshot metadata.

** Checking the extent ref tree.

** Checking the fsroot tree.

** Checking volume.

** Checking the APFS volume superblock.

** The volume VM was formatted by newfs_apfs (748.67.14) and last modified by apfs_kext (945.230.6).

** Checking the object map.

** Checking the snapshot metadata tree.

** Checking the snapshot metadata.

** Checking the extent ref tree.

** Checking the fsroot tree.

** Verifying allocated space.

** Performing deferred repairs.

** The volume /dev/rdisk1 appears to be OK.

AirdiRiaMengoli:Library ritamengol$

AirdiRiaMengoli:Library ritamengol$ sudo tmutil listlocalsnapshots /

Password:

com.apple.TimeMachine.2018-12-31-164401

com.apple.TimeMachine.2019-01-01-134732

com.apple.TimeMachine.2019-01-01-144438

com.apple.TimeMachine.2019-01-01-161515

AirdiRiaMengoli:Library ritamengol$

I've done it!

I deleted all new Time Machine local snapshot and then I changed the usb drive I was using: probably it was not good for this job.

Now Windows is ok.

But now there is something wrong in macOS: it looks like "Macintosh HD" is not a start up drive. this happen both in Boot Camp preferences, when running Windows (only BOOTCAMP drive is shown) and in macOS system preferences (both partition are shown, but macOS one can't be selected).

The only way I can start macOS is press option hey when starting the MacBook Air and then select Macintosh HD.

I think it is not normal.

I partially fixed the last issue, one described in previous post.

Now I can set Macintosh HD as default start up drive in macOS, but I still can't do it in Windows, using Boot Camp Utility.

Thank you a lot for your help.

I've done as you wrote.

Now there is no alert about not enough space, but the result is the same: it is not possible saving support software...

And I still don't understand why.

Ah, ok.

Please, tell me about two other methods, I'd like to try them.