Serializtion problem in C#

nelo
the problem is solved but i don't know why
code you pls explain why this is the solution for my issue

You should mark your events as [field: NonSerialized]. If you think about it, it makes sense. Your events are basically lists of delegates, which are pointers to functions of other objects. When sending around serialized data, those objects probably won't even exist, which causes problems :). Your main form class was listening to one of those events, and it is not serializable.