I'm up to Chapter 20a in the book with no problems yet. However, when I tried to create a new ADO.NET Entity Data Model using Tasks.mdf I receive the following verbose message:
"The header for file: [file path]\Tasks.mdf is not a valid database header file. The FILE SIZE property is incorrect.
An attempt to attach an auto-named database for file [file path]\Tasks.mdf failed. A database with the same name exists, or specified file cannot be opened, or is it located on an UNC share."
One website said that this error means the mdf has become corrupt, so I tried re-downloading and received the same message. Thoughts?