GPConnection.Connect() exception: Timeout expired.

This article replaces TK00126.


When you launch Dynamics GP for the first time after a new install or upgrade, the Project Cost Addin failed to load and you receive the following error.

GPConnection.Connect() exception: Timeout expired. The timeout period elapsed 
prior to obtaining a connection from the pool. This may have occurred because all 
pool connections were in used and max pool size was reached.


  1. Users or group does not have full control over the directory.
  2. Windows blocked files during the Project Cost install process.
  3. TCI/IP protocol for Dynamics GP in SQL Server Configuration Manager is disabled.
  4. SQL Server Browser is not running.


Resolution 1:

Give users or group full control over the directory.

  1. Locate the AddIns folder in the Dynamics GP root directory.
  2. Right-click, select Properties, and select the Security tab.
  3. In the list, select a group or user name and click Edit.
  4. Mark the box for Full control, click Apply, and then click OK.
  5. Close the Properties window and relaunch Dynamics GP.

Resolution 2:

The following KB provides the steps on how to unblock Project Cost files.

Dynamics GP Not Launching After New Client Workstation Install

Resolution 3:

The following KB provides the steps on how to enable the TCI/IP protocol.

IsModuleRegistered failed

Resolution 4: 

Turn on SQL Server Browser.

  1. Click Windows Start and open Services app.
  2. Double-click on SQL Server Browser and perform the following.
    1. Change the Startup Type to Automatic.
    2. Click Start.
    3. When the service starts, click Apply and then OK.
    4. Close the Services app.