Login Error: Communication protocol mismatch between client and server for NAV 2013

There are times when logging into NAV 2013 that you will be prompted for a username and password. But after entering the proper credentials, you receive an error prompt that says, “There is a communication protocol mismatch between the client and the server,” as shown below.

Figure 1 – NAV error prompt stating there is a protocol mismatch between the client and server

If you use Windows credentials, the system should not prompt for username and password. Instead, it should authenticate using your Windows domain credentials. So, if you ever see this error, then it is because of setting in ClientUserSettings.config file.

Cause:

The ClientUserSettings.config file is set to use NavUserPassword as the Credential Type

Resolution:

Open ClientUserSettings.config file and change the ClientServicesCredentialType to Windows.

Figure 2 – Line from ClientUserSettings.config file showing how to correct the protocol mismatch error

The default path for the file is

 C:\Users\<user name>\AppData\Roaming\Microsoft\Microsoft Dynamics NAV\70

For more information on topics related to Microsoft Dynamics NAV development, read the ArcherPoint Developer Blog, written specifically for Dynamics NAV developers, or contact ArcherPoint directly.