`Failed to get file descriptor 0` issue on Final Fantasy XIV discs

[Whovian9369]

$ ~/path/to/UnshieldSharp-9dc403ffc18d60c3016fcfbbd5499ee275a46ced_net6.0_linux-x64_1.6.9-55/Test -o data1_hdr data1.hdr
Failed to get file descriptor 0
Unhandled exception. System.ArgumentNullException: Value cannot be null. (Parameter 'source')
   at System.Linq.ThrowHelper.ThrowArgumentNullException(ExceptionArgument argument)
   at System.Linq.Enumerable.Select[TSource,TResult](IEnumerable`1 source, Func`2 selector)
   at Test.Program.ProcessCabinetPath(String file, Boolean outputInfo, Boolean extract, String outputDirectory) in C:\projects\unshieldsharp\Test\Program.cs:line 251
   at Test.Program.Main(String[] args) in C:\projects\unshieldsharp\Test\Program.cs:line 94
[1]    228259 abort       -o data1_hdr data1.hdr

Ran Test -i data1.hdr to see if it still errored or not, and it did after listing a number of other files first: UnshieldSharp_Error.log

Small edit: So I decided to look at the log info again right after posting this issue, and found that it seems to fail at getting the following file descriptors before giving the above error:

Failed to get file descriptor 0
Failed to get file descriptor 1
Failed to get file descriptor 7
Failed to get file descriptor 8
Failed to get file descriptor 9
Failed to get file descriptor 10
Failed to get file descriptor 51
Failed to get file descriptor 58
Failed to get file descriptor 59
Failed to get file descriptor 126