Problem ( A look-up field contains invalid data. Please check the value and try again. ) with uploading documents to SharePoint Document Library.

When you upload a document to Document libary you may get an error message 'Invalid look-up value. A look-up field contains invalid data. Please check the value and try again.'

This indicates a problem with document properties. You can fix this by using 'Document Inspector' in MS Office 2007(Word, PowerPoint or Excel). The document inspector can be accessed using 'Home>Prepare>Insepect Document'.

In the 'Document Inspector' window select the option 'Remove All' to clear the document properties.

Now save and upload the document again and you may not receive the error message ('Invalid look-up value. A look-up field contains invalid data. Please check the value and try again.')