Troubleshooting

Problem: Hyper-V Reserving AppEngine Default Port 54001

On some Windows systems, Hyper-V networking may reserve TCP ports that CompuTec AppEngine needs to start. When this happens, CompuTec AppEngine can't use its default port 54001, and the service doesn't start.

When Hyper-V is turned on, the Windows NAT (WinNAT) service may automatically reserve certain port ranges for virtual networking. If port 54001 is included in one of these ranges, CompuTec AppEngine cannot bind to it, even though nothing else seems to be using it.

You may see one or more of the following symptoms:

• The CompuTec AppEngine service doesn't start or stops immediately after starting.
• Log files or Windows Event Viewer show messages such as: Address already in use or Failed to bind to port 54001.
• No other visible application appears to be using port 54001.

Solution

note

• You must run these steps as a local administrator.
• Stopping WinNAT may temporarily interrupt networking for virtual machines, for example, Docker.

1. Close CompuTec AppEngine and any related admin tools. If CompuTec AppEngine runs as a Windows service, stop it from Services.
2. Find Command Prompt in your Start menu, right-click on it and select Run as administrator.
3. Run the following command: net stop winnat to stop the WinNAT service.
4. Wait until Windows confirms that the service has stopped.
5. Run the following command: net start winnat to start the WinNAT service again.
6. Once restarted, Windows recalculates the reserved port ranges. In many cases, this frees port 54001 so CompuTec AppEngine can start normally.
7. Done! Now you can start CompuTec AppEngine again.

If the problem persists

If AppEngine still cannot start after restarting WinNAT:

• Confirm that no other service is configured to use port 54001.
• Check with your system administrator whether other network tools (Docker, WSL2, additional Hyper-V setups) are reserving the same port range.
• Consider changing the CompuTec AppEngine port (if supported in your configuration) to a port outside the reserved range.

info

If you need help, or have any questions, contact us via the CompuTec Helpdesk Portal.

Problem: CompuTec AppEngine doesn't connect to the database

CompuTec AppEngine fails to connect to the SAP HANA database, and the following error is displayed:

Could not load file or assembly 'Sap.Data.Hana.Core.v2.1, Version=2.7.26.0, Culture=neutral, PublicKeyToken=0326b8ea63db4bc4'. Could not find or load a specific file. (0x80131621).

Solution

You have to ensure that the SAP HANA Database (HDB) Client installed on the system where CompuTec AppEngine runs matches the SAP HANA server revision. It's important that the environment variable path is correctly pointing to the installation directory.

To check the environment variable path, follow these steps:

1. Go to Windows > System Properties > Environment Variables....

   

2. Locate the variable named HDBDOTNETCORE and note the path. In our example, it's C:\Program Files\hdbclient\dotnetcore.

   

3. Open the noted path on your computer.

4. Find the libadonetHDB.dll file, right-click on it, and click Properties.

5. Check its Product version. It must match the HANA Server Revision.

   

6. Done! Now you know if the environment variable path is correctly pointing to the installation directory.

Problem: Some features are disabled after CompuTec AppEngine upgrade

After upgrading CompuTec AppEngine, some or all CompuTec AppEngine features appear disabled or unavailable.

Solution

To resolve this issue, follow these steps:

1. Log in to CompuTec AppEngine Administration Panel.

2. Navigate to Configuration.

3. Review the list of your companies.

4. Click the Update required label and complete the guided steps to finish the company update process.

   

5. Done! Now all features are active.