Why are some of my migrated tables showing "The given key was not present in the dictionary" in WebMatrix's interface? I'm having an issue while using the SQL Server Migration tool to convert Access accdbs into SQL Server 2014 Express. I am converting the tables using SQL Server Migration Tool and I have a connection string to the SQL Server 2014 Express database in WebMatrix. All of the tables show up, but, for some reason, many of the tables, when I try to open them in WebMatrix, show an error "The given key was not present in the dictionary. Like so:



During the conversion, it shows "0" errors and proceeds as though everything is okay. This seems to be an issue with WebMatrix, because, not only are the tables openable in SQL Server Management Studio (showing all rows), but they are also queryable, meaning that the information is there:



It just won't show in WebMatrix's interface if you try to open the whole table.

I would like for this to work in WebMatrix and was wondering if anyone could help or has encountered this before. I try to search Google, but nothing relevant comes up. That's usually the case when trying to research WebMatrix specific problems.
Here is what you need to do


Open the table in definition view
Select a cell in the column which is empty. 
Add an entry of that data type (I picked the datetime in an example where this happened to me)


When done, you should be able to click the data button and see all the data.