ExeConfigurationFileMap: InvalidArgumentException, The string parameter 'fileMap.ExeConfigFilename' cannot be null or empty

Question

I am getting an InvalidArgumentException when I run my application. I am attempting to create a new ExeConfigurationFileMap, and then load it with ConfigurationManager.

    public static ExeConfigurationFileMap configFile = new ExeConfigurationFileMap(Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData) + "\\QuikSnap\\QuikSnap.config");
    public static Configuration config = ConfigurationManager.OpenMappedExeConfiguration(Settings.configFile, ConfigurationUserLevel.None);

I have also attempted to set the configuration file after declaring it, but still didn't have any luck.

If I attempt to continue after this exception, I next receive a TypeInitalizationException upon trying to set a variable to one of the values in the configuration file.

Answer 1

Ran into this same problem. For some ridiculous reason, initializing ExeConfigurationFileMap even with the filepath does not set the property ExeConfigFilename which is required by the Configuration objects constructor. I fixed it by immediately setting that property after instantiating the ExeConfigurationFileMap object like below:

public static ExeConfigurationFileMap configFile = new ExeConfigurationFileMap(Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData) + "\\QuikSnap\\QuikSnap.config");
configFile.ExeConfigFilename = "QuikSnap.config";
public static Configuration config = ConfigurationManager.OpenMappedExeConfiguration(Settings.configFile, ConfigurationUserLevel.None);