Trying to use an SPWeb object that has been closed or disposed and is no longer valid.

using (SPWeb ospWeb = SPContext.Current.Web)
{
//...Logic
}

 Page  error “Trying to use an SPWeb object that has been closed or disposed and is no longer valid.”

 Modified the code as shown below: 

using(SPSite spSite=new SPSite(SPContext.Current.Web.Url))

{

using (SPWeb spWeb = spSite.OpenWeb())

{

//...Logic

}

}

 MSDN click here