Error: 'ParentTableName' is not a member of type 'EntityModel.ChildTableName' in the currently loaded schemas. Near simple identifier, line 6, column 4.

•  MAKE sure tables are related  (primary - foreign keys are set)
•  Note that 

it.ParentTable.Id= @SomeId - tells db to load only items that have that @SomeId

•  MAKE sure name in where parameters is correct (usually the same as QueryStringField)

   <WhereParameters>
          <asp:QueryStringParameter Name="SomeId" QueryStringField="SomeId" Type="Int32" />
    </WhereParameters>

VB.NET - Excel - Hide Column

osheet.Range("L" & curLine).Columns.Hidden = True
Or
osheet.Range("H1").ColumnWidth = 0
Remember, the following line will unhide columns
osheet.Range("A" & intHeaderLine, "BH" & curLine).EntireColumn.AutoFit()

Error 'AsEnumerable' is not a member of 'System.Data.DataTable'

add the following reference to the project (Project/Add Reference)
C:\Program Files\Reference Assemblies\Microsoft\Framework\v3.5\System.Data.DataSetExtensions.dll

Error: Maximum request length exceeded

Modify Machine.Config file
Add <httpRuntime maxRequestLength="8192" /> under <system.web>


  <system.web>
<httpRuntime maxRequestLength="8192" />

Machine.config is usually located in (you may have different folder name under Framewok:
c$\WINDOWS\Microsoft.NET\Framework\v2.0.50727\CONFIG