DeclarationError: Identifier not found or not unique.

[KartikeyCode]

I have no Idea why I am getting this error. Please help

[othaime-en]

Make sure the contract name in your SimpleStorage.sol file is SimpleStorage.
The name of the contract being inherited in the line contract Extra is SimpleStorage should always be the same as the contract name itself, not the contract file name.
You usually get this error when there is a mismatch between the contract you are trying to inherit and its actual name. i.e. a spelling mistake or when the contract you are inheriting doesn't exist.

[krakxn]

Context is necessary for people to comprehend the problem, a screenshot does not help really.

In any case, the problem lies in the import here. Verify if the path is correct.