Cannot save all of the property settings for this Web Part - Sharepoint -

"cannot save of property settings web part. default namespace "http://schemas.microsoft.com/webpart/v2" reserved namespace base web part properties. custom web part properties require unique namespace (specified through xmlelementattribute on property, or xmlrootattribute on class)."

no regarding error.

this when adding custom properties webpart, why cant save properties when edit webpart , click on save/apply? (then error)

code--

     [defaultproperty("text"), toolboxdata("<{0}:custompropertywebpart runat=server></{0}:custompropertywebpart>"),             xmlroot(namespace = "executestoreproc")]             public class custompropertywebpart : microsoft.sharepoint.webpartpages.webpart             {                 const string c_mystringdefault = "sample string";             }              // create custom category in property sheet.             [category("custom properties")]             // assign default value.             [defaultvalue(c_mystringdefault)]             // property available in both personalization             // , customization mode.             [webpartstorage(storage.personal)]             // caption appears in property sheet.             [friendlynameattribute("custom string")]             // tool tip appears when pausing mouse pointer on         // friendly name in property pane.         [description("type string value.")]         // display property in property pane.         [browsable(true)]         [xmlelement(elementname = "mystring")]          // accessor property.         public string mystring         {                         {                 return _mystring;             }             set             {                 _mystring = value;             }         } 

can try going site settings > galleries > web part > new in window, put checkbox next webpart trying add, click populate

if populate correctly working otherwise there error in webpart.

return webpage want add webpart, try add webpart selecting in gallery.

if works (you able add page), can open webpart added in webpart gallery (site settings > galleries > web part) , compare own .dwp file see did wrong.

hope helps