Dropbox.Api.Sharing.ListFileMembersAsync Invalid Path after passing FileMEtadata.Id

A customer of ours is running into the error below:

System.ArgumentOutOfRangeException: Value should match pattern '\A(?:((/|id:).*|nspath:[0-9]+:.*)|ns:[0-9]+(/.*)?)\z' Parameter name: file

at Dropbox.Api.Sharing.ListFileMembersArg..ctor(String file, IEnumerable`1 actions, Boolean includeInherited, UInt32 limit)

at Stealthbits.StealthAUDIT.DataCollectors.Dropbox.Tasks.Scan.DropboxScanHelper.<>c__DisplayClass58_4.<ProcessResources>b__6()

at Stealthbits.StealthAUDIT.DataCollectors.Dropbox.Tasks.Scan.DropboxScanHelper.AwaitReturn[TResult](Func`1 callback)"

 

I censored the path for the customer but the structure is the same as the path below.
Failed to process resource /3- Folder1/1 - Folder2/Folder3 - Folder3 - Folder3/1 - Folder4/01.23.4567: File File_File_01.23.4567.pdf

 

Code using Dropbox 4.9.4, I will try updating to 5.5.0 (6.8 is giving me dependency errors):

 

 

userClient = client.AsMember(member.Profile.TeamMemberId);
adminClient = userAdmin.WithPathRoot(new PathRoot.NamespaceId(namespaceID));
var FolderContents = AwaitReturn(() => adminClient.Files.ListFolderAsync(namespaceID, false, true, false, true));
var entries = FolderContents.Entries;
while (FolderContents.HasMore)
{
    FolderContents = AwaitReturn(() => adminClient.Files.ListFolderContinueAsync(FolderContents.Cursor));
    foreach (var entry in FolderContents.Entries)
    {
	    entries.Add(entry);
    }
}


foreach (Metadata resource in entries)
{
    if (resource.IsFile)
    {
        List<Sharing.UserMembershipInfo> users = new List<Sharing.UserMembershipInfo>();
        FileMetadata fileData = resource.AsFile;
        //Errors here
        var fileMembers = AwaitReturn(() => 
        userClient.Sharing.ListFileMembersAsync(fileData.Id));
        users.AddRange(fileMembers.Users);

        while (!String.IsNullOrEmpty(fileMembers.Cursor))
        {
            fileMembers = AwaitReturn(() => userClient.Sharing.ListFileMembersAsync(fileMembers.Cursor));
							 
            users.AddRange(fileMembers.Users);
        }

        foreach (var member in users)
        {
            //Process member
        }
    }
}


TResult AwaitReturn<TResult>(Func<Task<TResult>> callback)
{
    using (Task<TResult> task = callback())
    {
	    task.Wait();
	    return task.Result;
    }
}