Why does my EPiServer installation crash when I am installing templates?

If you are installing EPiServer and receive the error message "Object reference not set to an instance of an object" during the template installing phase, this might very well be due to a missing setting in Web.config.

This issue occurs when you are installing EPiServer with an Enterprise license without taking the appropriate configuration steps needed for EPiServer Enterprise. The installation process tries to access a section in Web.config that is required for Enterprise configuration and crashes when this section cannot be found.

An example of the stack trace for this error:

NullReferenceException: Object reference not set to an instance of an object.]
EPiServer.ConfigFileSettings.ᐃ() +69
EPiServer.ConfigFileSettings.ᐂ() +87
EPiServer.ConfigFileSettings.SetAppSetting(String name, String val) +21
EPiServer.ApplicationConfiguration.Persist() +373

Add the following configuration handler and enterprise section to web.config immediately after the opening <configuration> tag:

For more information concerning Enterprise configuration, please read the tech note Configuring EPiServer Enterprise Edition.