HTTP Response Error: 404, Unexpected System.NullReferenceException: Object reference not set to an instance of an object

After restoring content database, we were getting 404 error into one of the web front server. We all were surprised to see this error because we followed same exact steps for restoring content database.  We have found issue is related to web front end server caching.

Here is very good link which is talking about issue and how to resolve this issue : http://myspworld.wordpress.com/2012/02/06/unexpected-system-nullreferenceexception/

Content Query Web Part - The web part references an untrusted XSL file. Only XSL files contained in this site's Style Library may be referenced

Content Query Web Part stop working after migration of SharePoint 2010. I have found same issues into other sites in which I have used content query web part. Error seems to be useful which means I need to upload my custom style sheet XSL file into site collection’s style library only.

In SharePoint 2007 - I have uploaded XSL file into different location, so to resolve this error we have to refer custom style sheet from site collection’s style library. After uploading XSL into correct folder, I am able to see the results for content query web part into SharePoint 2010.

Visual Studio Business Intelligence Project templates missing

With Business Intelligence Project templates from Visual Studio we can create SQL Server Reporting Service projects (SSRS). I was missing “Business Intelligence Project” templates in visual studio and I was sure that I have installed full version of Visual Studio into my computer, still I was not getting Business Intelligence templates.

After searching little bit online, I have found Business Intelligence templates are associated from SQL Server installation, when we are installing SQL Server into computer at that time we have to select “Business Intelligence Development Studio” to install project templates to create SSRS reports.

Here is link which explain very well about how to install Business Intelligence Project templates into Visual Studio: 

http://crmconsultancy.wordpress.com/2010/06/03/installing-visual-studio-for-sql-reporting-services-development/

Differences between choice and lookup SharePoint columns

Very good and useful differences between choice and lookup SharePoint columns:

http://cloud.snappages.com/b8898dc2c08e137d03449de65b9e82e108c15658/Choice_v_Lookup_Column_Tradeoffs.pdf

Web service error : There was an error deserializing the object of type. The maximum array length quota (16384) has been exceeded while reading XML data

When we are calling SharePoint web services from .NET client and if we are passing large amount of data and variables to web services then at that time we need to make sure that we are changing MaxArrayLength property into client application web.config file. Generally setting 2147483647 value for MaxArrayLength property into web.config file resolve the problem.

Reference Links:

http://stackoverflow.com/questions/464707/maximum-array-length-quota

http://stackoverflow.com/questions/1589750/wcf-string-element-nillable-false