Problem.

In general, this problem may manifest itself in different ways. In my case, it was SharpDevelop, which completely refused to compile Hello world, which in the command shell (including through NAnt) is assembled without errors. At the same time, SharpDevelop was stingy with information:

After about an hour of bydlokoding and finding the source of the problems, the development environment agreed to supplement the information about the error with new useful information:

Decision.

The environment variable “ MONO_EXTERNAL_ENCODINGS ” is created with the value “ default_locale ”, the command shell or development environment is restarted. In my case, the problem no longer manifests itself.