Case 1:
1) Open Web Service Model in Model Editor
2) Select Web Service Interface in Model explorer
3) Right-click select New > Child > Operation
4) New Operation shows up in Explorer, but auto-rename is not enabled.
Case 2:
1) DO NOT open Web Service model in Model Editor (i.e. close all editors)
2) Select Web Service Interface in Model explorer
3) Right-click select New > Child > Operation
4) New Operation shows up in Explorer, but auto-rename is not enabled.