This issue happens after you have upgrade Test Manager to a new version and the password can not recognized by the new software, in order to avoid this, please follow below steps to clear this issue
1, After you have upgrade Test Manager, you should go to Help->About->Password.
2, backup you password to select -> Export->comma separated file (.csv).
3, Manually delete all the password of the test pack.
4, Import the password that has been backup as Step 3.
After you have done the step above, you will never see Feature ID is not valid in the Test Manager and you can continue your testing.