cannot find libui.dll

[Shadowblitz16]

'Mono-Test.exe' (CLR v4.0.30319: DefaultDomain): Loaded 'C:\Windows\Microsoft.Net\assembly\GAC_32\mscorlib\v4.0_4.0.0.0__b77a5c561934e089\mscorlib.dll'. Skipped loading symbols. Module is optimized and the debugger option 'Just My Code' is enabled.
'Mono-Test.exe' (CLR v4.0.30319: DefaultDomain): Loaded 'C:\Users\shadowblitz16\Documents\Visual Studio 2017\Projects\Mono-Test\Mono-Test\bin\Debug\Mono-Test.exe'. Symbols loaded.
'Mono-Test.exe' (CLR v4.0.30319: Mono-Test.exe): Loaded 'C:\Users\shadowblitz16\Documents\Visual Studio 2017\Projects\Mono-Test\Mono-Test\bin\Debug\DevZH.UI.dll'. Skipped loading symbols. Module is optimized and the debugger option 'Just My Code' is enabled.
'Mono-Test.exe' (CLR v4.0.30319: Mono-Test.exe): Loaded 'C:\Windows\Microsoft.Net\assembly\GAC_MSIL\System.Runtime\v4.0_4.0.0.0__b03f5f7f11d50a3a\System.Runtime.dll'. Skipped loading symbols. Module is optimized and the debugger option 'Just My Code' is enabled.
'Mono-Test.exe' (CLR v4.0.30319: Mono-Test.exe): Loaded 'C:\Users\shadowblitz16\Documents\Visual Studio 2017\Projects\Mono-Test\Mono-Test\bin\Debug\System.Text.Encoding.CodePages.dll'. Skipped loading symbols. Module is optimized and the debugger option 'Just My Code' is enabled.
'Mono-Test.exe' (CLR v4.0.30319: Mono-Test.exe): Loaded 'C:\Windows\Microsoft.Net\assembly\GAC_MSIL\System.Text.Encoding\v4.0_4.0.0.0__b03f5f7f11d50a3a\System.Text.Encoding.dll'. Skipped loading symbols. Module is optimized and the debugger option 'Just My Code' is enabled.
'Mono-Test.exe' (CLR v4.0.30319: Mono-Test.exe): Loaded 'C:\Windows\Microsoft.Net\assembly\GAC_MSIL\System.Threading\v4.0_4.0.0.0__b03f5f7f11d50a3a\System.Threading.dll'. Skipped loading symbols. Module is optimized and the debugger option 'Just My Code' is enabled.
'Mono-Test.exe' (CLR v4.0.30319: Mono-Test.exe): Loaded 'C:\Windows\Microsoft.Net\assembly\GAC_MSIL\System.Core\v4.0_4.0.0.0__b77a5c561934e089\System.Core.dll'. Skipped loading symbols. Module is optimized and the debugger option 'Just My Code' is enabled.
'Mono-Test.exe' (CLR v4.0.30319: Mono-Test.exe): Loaded 'C:\Windows\Microsoft.Net\assembly\GAC_MSIL\System\v4.0_4.0.0.0__b77a5c561934e089\System.dll'. Skipped loading symbols. Module is optimized and the debugger option 'Just My Code' is enabled.
'Mono-Test.exe' (CLR v4.0.30319: Mono-Test.exe): Loaded 'C:\Users\shadowblitz16\Documents\Visual Studio 2017\Projects\Mono-Test\Mono-Test\bin\Debug\System.Console.dll'. Skipped loading symbols. Module is optimized and the debugger option 'Just My Code' is enabled.
'Mono-Test.exe' (CLR v4.0.30319: Mono-Test.exe): Loaded 'C:\Users\shadowblitz16\Documents\Visual Studio 2017\Projects\Mono-Test\Mono-Test\bin\Debug\Microsoft.Win32.Primitives.dll'. Skipped loading symbols. Module is optimized and the debugger option 'Just My Code' is enabled.
'Mono-Test.exe' (CLR v4.0.30319: Mono-Test.exe): Loaded 'C:\Windows\Microsoft.Net\assembly\GAC_MSIL\System.Runtime.InteropServices.RuntimeInformation\v4.0_4.0.0.0__b03f5f7f11d50a3a\System.Runtime.InteropServices.RuntimeInformation.dll'. Module was built without symbols.
Exception thrown: 'System.DllNotFoundException' in DevZH.UI.dll
An unhandled exception of type 'System.DllNotFoundException' occurred in DevZH.UI.dll
Unable to load DLL 'libui': The specified module could not be found. (Exception from HRESULT: 0x8007007E)

'Mono-Test.exe' (CLR v4.0.30319: Mono-Test.exe): Loaded 'C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\common7\ide\PrivateAssemblies\Runtime\Microsoft.VisualStudio.Debugger.Runtime.dll'. Skipped loading symbols. Module is optimized and the debugger option 'Just My Code' is enabled.
The program '[1380] Mono-Test.exe' has exited with code -1 (0xffffffff).```