Can not move products to categories

[bluecherry]

I imported 200+ products using the dataport utility...however they were not dumped into a category so they are just all hanging out. I'm trying to move each one individually and getting this error:

Server Error in '/' Application.
Object reference not set to an instance of an object.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.
[NullReferenceException: Object reference not set to an instance of an object.]
ASP.admin_catalog_movecatalogobject_aspx.SaveButton_Click(Object sender, EventArgs e) +301
System.Web.UI.WebControls.Button.OnClick(EventArgs e) +105
System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) +107
System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +7
System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +11
System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +33
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +5102

[mazhar]

Please post detailed error message from app_log or from Admin -> Help -> Error log page

[bluecherry]

There is no error(s) relating to this in Admin -> Help -> error log

Please post detailed error message from app_log or from Admin -> Help -> Error log page