[Pharo-users] Problem with adding an instance variable to SmalltalkImage

Hello everyone, when I try to add the instance variable foo to SmalltalkImage I get a popup asking me "CompilerCLass is still used in code of class SmalltalkImage. Is it okay to move it to undeclared" It's the same for any instanceVariable Is it normal ? If it's normal should I answer yes or no ? Valentin