Mike,
Type Ribbon at the command prompt and verify if ribbon tabs/panels appear. Else follow below steps.
Command wscurrent--> enter StructureCommand wscurrent-->Enter Mechanical
If you still have the issue;
On the command line, enter menuload and unload all the customization groups-->closeMenuload--> Select browse and load the acadM.CUI from acadm folder. ( C:\Documents and Settings\User login name\Application Data\Autodesk\AutoCAD Mechanical 2010\R18.0\enu\Acadm\)Click Load and then click CloseCommand wscurrent-->Enter Mechanical
Let me know if this helps.
Thanks,
Sridhar
Software QA Engineer
Autodesk, Inc.
Please select the Accept as Solution button if my post solves your issue or answers your question.
Sridhar Subramani
Senior Product Owner