Error creating Hovertcraft NSP

[snucker]

[6/28/2023 4:45:24 PM] Progress: Extracting files from the Manual NCA... - 30%
[6/28/2023 4:45:24 PM] Progress: Extracting files from the Update Manual NCA... - 38%
[6/28/2023 4:45:24 PM] Progress: Shuffling files... - 46%
[6/28/2023 4:45:25 PM] Could not find a part of the path 'C:\Users\snucker\Downloads\CaVE\1.5 beta\CaVE-v1.5-Alpha1\cache\Hovercraft_exefs_1_1_1\main'. (A)
at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
at System.IO.File.InternalCopy(String sourceFileName, String destFileName, Boolean overwrite, Boolean checkHost)
at System.IO.File.Copy(String sourceFileName, String destFileName, Boolean overwrite)
at Hovercraft.HovercraftSetup.g()

[Dark Akuma]

This appears to be caused from opening the update select dialog, selecting All Files, and force selecting a .nsz instead of a .nsp.

Due to the nature of the process it cant exactly know that the provided file is not valid until this progress process starts.

I should probably remove the All Files option, but I like having such options for advanced users. And if I was to remove that here, I should remove it a lot of places in the program.

For now, all I can do if provide a clearer message when the issue happens. It will now check for the file before copying it, and throw an error with a better message.

[snucker]

Confirmed to work when use a NSP, NSZ causes the error.