Here is a common scenario.

On user PC the application is not loading throwing a standard error message (send error report /do not send/debug). This message appears before the code is implemented, and it is visible only for user. And even user hit “Send” button, then the report will go to abstract “helpdesk”, and not necessarily to the developer.

If the user PC is available to me, then I can debug there and see what is missing (it may be some dlls/references that were not copied into application directory, limited user privileges to access folders or SQL Server, etc.)

Had it happened during the code execution, then I would get the error message and description via email (following onerror or try&catch routine), but the code is not yet started.

How do you handle this situation?