Re: UFT gives - sequence contains more than one matching element error.
This error occurs when you have incorrect action references in the solution.
Probable cause: You initially created a solution and saved it to UFT. Then edited the action calls and tried to check in again when the error occurs
To fix this go to:
View -> Solution Explorer -> External Actions
See which are the correct actions and remove the others and then check in. It is adviced to keep different action names always, since same action names in different ALM directories can cause this issue.