I you have created a new database there are no page with id 27, rather 3 or 4.
I would copy the database to your local enviroment to get the best result, but you can of course also change tha startpageid to 3 (I think) in your config
I have set the pagestart id to 1 and also tried for 3 also now I am getting error in this section of the code
PropertyCriteria criteria = new PropertyCriteria();
criteria.Value = PageType.Load("Klinikstartsida").ID.ToString();
it is not strange that you get this error since you try to load a pagetype that propably does not exist and do a toString on a property for a object that possible is null.
If you have a lot of stuff like that in the code, it is better to restore the database in your local enviroment.
Utpal, do not forget to mark answers that solves you problem.
I have got an existing Episerver 6 project from client and for some modification i have to run this in my local development machine.I have successfully complied the project but when I am running the project I am getting the error Page 27 was not found and in my configuration I have set the pagestartid as '27'. What I suspect that I have only bring the code files for the project and not copy the databases with data in my local development data.I have created a Episerver site and used the database of that site to run my project.Is it the reason I am getting this error?Please help.