Question:

How come that some of my web visitors and editors receive strange error messages, while others get a white page with explanatory text? 

Answer:

Most likely the strange looking error message is generated by the .NET environment in which EPiServer is built. However, in EPiServer there is a setting where you can get rid of .NET error messages, and adapt the appearance.

The first setting is done in Admin mode under the tab Config/ System Settings. Under the alternative  "Error handling in EPiServer", you can decide whether the more "user friendly" messages should be activated in the following way:

1. Active for remote visitors (visitors not logged in)
2. Active for all (visitors and editors)
3. Error handling off

The most common is to activate this setting for all, to avoid hard-to-interpret error messages to reach the editors if something goes wrong.

However, if you activate this setting for everyone, it also means that you will activate it for administrators and developers. If so, it will be more difficult to find the cause of a problem, since it will be trickier to interpret the error correctly. To manage this, it is possible to allow display of detailed error messages to certain groups or users. This is how it is done:

1. Select the tab Config/ Permissions for Functions.
2. Choose  "Detailed error messages for troubleshooting".
3. Add the groups or users who will receive the .NET environment related error messages
4. Choose Save.