Cannot comment on my own question and its answers after it was migrated - this is similar, but not the problem that I have.
Unable to comment on my own question after it was migrated/moved - almost it, except for the part that I do have a StackExchange account and all my accounts on StackExchange-related sites are connected (associated) with each other.
Here's my original question: http://serverfault.com/questions/526385
More details on what exactly happened:
I have an account on serverfault.com, but I don't have an account on unix.stackexchange.com. After I saw that the question was migrated, I followed the link and ran into some SO error (your typical ASP.NET error page telling you that something went wrong).
I've reloaded the page and was able to create an account using Google OpenID (that's the same mechanism I use for my other accounts on StackExchange).
Now, each time that I'm trying to visit Unix&Linux forum, I'm getting a technical error from StackExchange, if I am at the same time logged with Google OpenID. Otherwise, I can see the question, but since I'm not logged as the author of the question, I cannot comment or reply to other commenter.
I believe this must be some StackExchange bug, but I could be wrong.