Unable to establish connection to the database when using external connectionString.config file

[Jimmy]

When trying to open a report preview in the designer, I receive the following error:

An error has occurred while processing Map 'map1': Unable to establish a
connection to the database. Please, verify that your connection string is valid.
In case you use a named connection string from the application configuration
file, make sure the name is correct and the connection string settings are
present in the configuration file of your application. -------------
InnerException ------------- Format of the initialization string does not
conform to specification starting at index 0.

I chose the option to save the connection string, but my config file differs a bit from the typical setup. My connection strings are in a separate config file using the following syntax:

<connectionStrings configSource="myProjectConnections.config" />

The Report designer correctly added the connections to the myProjectConnections.config when I chose the option to save connections, but I have a feeling this is related to the designer failing to preview the report. In addition, the data sources in the data explorer, as well as the map wizard don't show or allow for the selection of the data sources I have added to the report.

Is this a known issue? Is there a workaround?

[Stef]

Hi Jimmy,

The stored by name connection strings must be copied in the start application configuration file in order to be accessible in the report. At design-time the start application is Visual Studio and the connection string settings and configuration files should be copied in the corresponding system folders and devenv.exe.config file.

I hope this information helps you.

Regards,
Stef
Telerik