Can't save or post to blogspot.com

Can't save or post!

 Type 'com.google.gwt.user.client.rpc.XsrfToken' was not assignable to 'com.google.gwt.user.client.rpc.IsSerializable' and did not have a custom field serializer. For security purposes, this type will not be deserialized.

Doesn't matter either Chrome or Firefox I am using.
Deleting cookies and temp files does not help either.
Open another new post, then Copy  & paste to the new post seems working.