Hi, I uploaded a slice to fogbugz which includes removing the class side Ivars from Collection to a new class managing a default random generator instance. The Monkey throws this error while checking: /Error: #Collection cannot be changed using the classbuilder. Use the reflective APi (e.g #addClassVariable:). If you know what you are doing, you can use #disableDuring: of DangerousClassNotifier/ Anyone know how to resolve this correctly? Case 16577: https://pharo.fogbugz.com/f/cases/16577 <https://pharo.fogbugz.com/f/cases/16577> Error message: https://ci.inria.fr/pharo/job/Pharo-5.0-Issue-Validator/13783//artifact/vali... <https://ci.inria.fr/pharo/job/Pharo-5.0-Issue-Validator/13783//artifact/vali...> Best regards, Henrik -- View this message in context: http://forum.world.st/Issue-validation-Collection-cannot-be-changed-using-th... Sent from the Pharo Smalltalk Developers mailing list archive at Nabble.com.