I checked the rest of the remoting questions, and this specific case did not seem to be addressed.
I have a .NET Remoting server/client set up. On the server side I
There are different reasons for this error, and you guys have mentioned more than a couple.
I have noticed another reason for this error; and that's when the constructor of the remotable object being called remotely throws and exception. the exceptions are not being serialized because the object itself wasn't initialized at that point. i believe you should avoid ANY code that might cause a custom exception to be thrown inside the remotable object's constructor. and if a system exception was thrown during the execution of the code inside the constructor, you should deal with it as a system error (unknown) and build a mechanism to store the details of that exception using the file system or whatever.
.net remoting sounded really appealing back in the days, but the larger your project gets, and the more concepts you introduce to your code, the more weaknesses this technology reveals. it's a good technology, but you need lots of experience to make a robust solution out of it.