After installing the business portal and configuring the terminal services for Dynamics GP, you might get the following error upon trying to open GP form:
"Null-CWTSSession.openCannes: 'oWTS' is null or not an object"
Through the business portal installation steps, you will need to adjust some settings on the internet explorer options as mentioned in the installation guide, below are the required steps, complete the steps and the error will no longer exist:
1. Start Internet Explorer and open the Internet Options window.
Tools > Internet Options
2. Click the General tab. Under browsing history, click Settings.
3. The Temporary Internet Files and History Settings window is displayed. Be
sure the Check for newer versions of stored pages option is not set to Never.
4. Click OK to close the settings window.
5. Click the Security tab, highlight Trusted Sites, and click Sites to open
the Trusted Sites window.
If Business Portal doesn’t use Secure Sockets Layer, you must clear the Require Server verification (https) for all sites in this zone check box. If you can’t clear the check box, you must change the security settings for the Local Intranet zone instead of adding Business Portal to your Trusted Sites list.
6. In Add this Web site to the zone, enter the Business Portal URL and click Add.
7. Click OK to close the Trusted Sites window.
8. In the Internet Options window, be sure Trusted Sites is still selected and click Custom Level to open the Security Settings window.
9. In the ActiveX controls and plug-ins section, select Enable for the following
• Download signed ActiveX controls
• Initialize and script ActiveX controls not marked as safe for scripting
• Run ActiveX controls and plug-ins
Changing these options will allow ActiveX controls to run automatically on all
web sites in your Trusted Sites zone. This zone contains sites that you
believe you can download or run files from without worrying about damage to your
computer or data. The security level for trusted sites is typically lower than the
general Internet or Intranet security level.
10. Click OK. An alert message will be displayed, asking if you’re sure that you want to change the security settings for the zone. Click Yes.
11. Click OK to close the Internet Options window.
Finally if you followed the above steps and still getting the problem, change the compatibility level in the internet explorer and it should no longer exist.