Environment

• Pythonnet version: 2.4.0.dev0 (master; #19d854c)
• Python version: 3.6.3 (v3.6.3:2c5fed8, Oct 3 2017, 18:11:49) [MSC v.1900 64 bit (AMD64)]
• Operating System: Windows 10 Pro 64 Bit (1803; 17134.5)

Details

• Describe what you were trying to get done.

1. Just callstr python built-in function with C# class
2. Raise UnicodeDecodeError if value is안녕
3. Return안녕PADD if value is `안녕PADDINGX"

It seems like failure str convert with ToString() function only.
(Another method, nor read value does not problem)

• What commands did you run to trigger this issue? If you can provide a
  Minimal, Complete, and Verifiable example
  this will help us understand the issue.

namespaceHello{publicclassWorld{publicstringvalue="안녕";publicstringGetString(){returnvalue;}publicoverridestringToString(){returnvalue;}}}

importclrclr.AddReference("hello")fromHelloimportWorldworld=World()print(1,str(world.value))print(2,str(world.GetString()))print(3,str(world))

• If there was a crash, please include the traceback here.

1안녕2안녕Traceback (mostrecentcalllast):File"main.py",line7,in<module>str(hello)UnicodeDecodeError:'utf-8'codeccan'tdecodebytesinposition0-1:unexpectedendofdata