For some reason I can't reproduce this problem all the time, it seems to mainly occur when you mess up an SQL Statement, here's what I did:
Open the .xsd using the designer
right click Fill, Getdata()
Click Configure
change the sql, I added in DATEPART(Month, Activedate)=DATEPART(Month, GETDATE())
I didnt propogate changes to the rest of the project.
Then ended up with the problem I described above.
I definately didnt change anything other than the SQL.
Infact i've just reproduced the error exactly by deliberately messing up the SQL, I did:
SELECT CompanyID, CompanyName, Address1, Address2, Address3, Address4, Address5, Postcode, Telephone, Fax, Website, Source, Marketer, Manager, Rep, Activemonth FROM dbo.Companies WHERE
DATEPART(Month, Activedate)=DATEPART(Month, GETDATE()<------------------------------------ Missing a )
The designer throws a warning saying to sql is incorrect then closes the sql window then if I click elsewhere in my project, ie one of the forms or any other part loads of errors start coming up in the error window such as:
Error1'CompaniesTableAdapter' is not a member of 'DataSetTableAdapters.TableAdapterManager'. Dialog2.Designer.vb4039
Even if I change the sql back to what it should be these errors remain and I end up with exactly the same problem, fortunately this time i'd backed up my project before doing it!
Hopefully this helps.
Cheers
Marc