I was trying to test a web service ... facing error while selecting the service

There's a cache for the WSLD and one for the data types.

A) If you think Appian is pulling out the old definition of the WSDL then the steps to perform are:

1. Delete the CDTs related to the Web Service. Make sure you delete all of them. Ideally you should sort by namespace to make sure you delete all of them.

It is very common for people to miss one or two making these steps fail

2. Open up the process model, right click on the Call Web Service Smart Service - Properties - Setup
3. Temporarily check Authentication Required and typed something in username and password and click Refresh
4. Uncheck the authentication required option.
5. Finish configuring the smart service.
6. Save and publish the model
7. Try again.

B) If the issue is the data types cache, again, this will be cleared after two hours, so I suggest you follow the step #1, restart your app server, wait two hours then try steps 2 to 7

There's a cache for the WSLD and one for the data types.

A) If you think Appian is pulling out the old definition of the WSDL then the steps to perform are:

1. Delete the CDTs related to the Web Service. Make sure you delete all of them. Ideally you should sort by namespace to make sure you delete all of them.

It is very common for people to miss one or two making these steps fail

2. Open up the process model, right click on the Call Web Service Smart Service - Properties - Setup
3. Temporarily check Authentication Required and typed something in username and password and click Refresh
4. Uncheck the authentication required option.
5. Finish configuring the smart service.
6. Save and publish the model
7. Try again.

B) If the issue is the data types cache, again, this will be cleared after two hours, so I suggest you follow the step #1, restart your app server, wait two hours then try steps 2 to 7