Sorry for the delayed response - I've had a chance to look at this and there is something wrong at your end.
To eliminate the plugin as being an issue, I used a tool called
SOAPUI. The version I am using is 5.2.1.
To get a positive result, I first pointed SOAP UI at the Jiwa sample web store to make sure I could get the CatalogTree:
Step 1.Open SOAP UI and create a new SOAP project by selecting the "Create New SOAP Project" button:
- Create New Project
- Step1-NewSOAP.PNG (15.58 KiB) Viewed 11614 times
Step 2.Enter the WSDL URL in the New SOAP Project dialog - note that it's different to the store URL - replace /index with ?wsdl=1 at the end of the URL. Make sure "Create Requests" is checked:
- New SOAP Project Dialog
- Step2-SetWSDL.PNG (21.46 KiB) Viewed 11614 times
Step 3.Locate the login request in the tree on the left - expand it and double-click the "Request 1" to open the request dialog. Replace the ? in the username and apiKey tags with the appropriate values. Press the Submit button (green arrow at the top left) to submit the request. The right hand pane will show the response - it contains the SessionId in the "loginReturn" tag - copy that as we need it for the next step.
- Login Request and Response
Step 4.Locate the catalogCategoryTree request in the tree on the left - expand it and double-click the "Request 1" to open the request dialog. Replace the ? in the sessionId tag with the value we got in the response from the previous step. Remove the ParentId and StoreView tags altogether (the plugin passes null for these values, so removing them simulates this). Press the Submit button (green arrow at the top left) to submit the request. The right hand pane will show the response - in this case with the Jiwa demo webstore the values are shown as expected.
- Catalog Category Tree Request and Response
Now, when I repeat this process with the details you provided for your store, I get either a fault or an empty response. When I get a fault it suggests in the response to check the logs.
So - you should turn on some logging and see what you can find there. Use a tool such as SOAP UI to test the requests as outlined above to speed up the debugging process.