Android Question Error When Generate Object to Activity

[PumaCyan]

I am trying to generate a panel object to the activity
then an error like this appears
please help, thank you

 

[DonManfred]

BBV1 or pnlDownload does not exists in this layout?

 

[PumaCyan]

I apologize
the problem was resolved after my project closed and then reopened
Sounds strange enough, but it works

 

[josejad]

Sounds strange enough

Strange? But if it's the solution to almost every single problem in computers. First step: "reboot the system".

 

[kisoft]

Hello...
From time to time it's worth cleaning the project (ctrl + p)