Hi Uden,

This error is often seen while the user attempts to check his inbox folders. This means there is something wrong with synchronization files which is preventing access to the inbox. This might occur because of email database Corruption on your computer.

 Follow the steps below to resolve this problem. 
 

Caution:  You will be unable to access e-mail messages saved in "Folders on my Computer" for all the accounts associated with MSN, after removing the MSN Explorer software. Hence before removal, make sure that you back up all archived e-mail messages that you may have saved on your computer, Go to  - http://answers.msn.com/solution.aspx?solutionid=d830f08c-414d-49ae-91cb-df58aa44832f for steps to back up your emails. When the MSN Explorer software has been successfully removed, restore your archived files by following the steps in the link - http://answers.msn.com/solution.aspx?solutionid=952151b9-f06b-4f52-8351-83e844e550b2 .

Once you have taken a back up sign out from MSN.

Locate the Msn folder in this location

For Windows XP :

C:\Documents and Settings\% YOUR USER NAME%\Local Settings\Application Data\Microsoft  
Under this folder locate MSN and rename to (MSN.old)


For Windows 7 & Vista :

C:\Users\%YOUR USER NAME%\AppData\Local\Microsoft\
Under this folder locate MSN and rename to (MSN.old)


Once you rename the Msn folder the issue should be resolved and then you can copy all your emails from saved location to folders on computer.
Sign out from Msn and Sign in again to check if the issue persist.


Thanks,
Nitesh