Show better error when file is used by another process

[bolbies]

Framework: .NET 8.0.2
RuntimeIdentifier: win-x64
OS: Microsoft Windows 10.0.26100

No mkv file info.

System.IO.IOException: The process cannot access the file 'D:\TV Streaming\TV Shows\Ajin\Season 01\Ajin (2016) - S01E01 - 001 - What Does That Stuff Have to Do With Us [Bluray-1080p][10bit][x265][AAC 5.1][EN+JA]-Prof.mkv' because it is being used by another process.
at Microsoft.Win32.SafeHandles.SafeFileHandle.CreateFile(String fullPath, FileMode mode, FileAccess access, FileShare share, FileOptions options)
at Microsoft.Win32.SafeHandles.SafeFileHandle.Open(String fullPath, FileMode mode, FileAccess access, FileShare share, FileOptions options, Int64 preallocationSize, Nullable1 unixCreateMode) at System.IO.Strategies.OSFileStreamStrategy..ctor(String path, FileMode mode, FileAccess access, FileShare share, FileOptions options, Int64 preallocationSize, Nullable1 unixCreateMode)
at System.IO.Strategies.FileStreamHelpers.ChooseStrategyCore(String path, FileMode mode, FileAccess access, FileShare share, FileOptions options, Int64 preallocationSize, Nullable`1 unixCreateMode)
at System.IO.File.Open(String path, FileMode mode)
at MatroskaLib.MatroskaReader.ReadMkvFiles(String[] filePaths)
at MatroskaLib.MkvFilesContainer..ctor(String[] filePaths)
at MkvDefaultTrackChanger.MainForm.LoadFiles()
at MkvDefaultTrackChanger.MainForm.BtnBrowseFilesClick(Object sender, EventArgs e)

[bolbies]

Lockhunter said nothing was using the files, but restarting the computer fixed it