Error message: Collection was modified; enumeration operation may not execute.

Url: https://dntech.gr/skin.aspx?lang=en&itemtype=ProductCategory&itemid=00000191&action=view&009A6BA4=009A6BA6‡009A6BA5‡009A6BAD‡009A6BA7‡009A6BAC‡009A6BAA‡009A6BAB‡009A6BA9‡009A6BA8&splitter_products_offset=24

Message: Collection was modified; enumeration operation may not execute.

   at System.ThrowHelper.ThrowInvalidOperationException(ExceptionResource resource)
   at System.Collections.Generic.List`1.Enumerator.MoveNextRare()
   at ASP.tpl_productcategory_view_tpl_ascx.__Render__control1(HtmlTextWriter __w, Control parameterContainer) in c:\inetpub\dntech.gr\tpl\ProductCategory.View.tpl.ascx:line 148
   at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children)
   at System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)
   at Bone.ActionView.Render(TextWriter w) in C:\Bone\Bone\src\Actions\DBActions\ActionView.cs:line 161
   at Bone.Action.RenderContent(TextWriter w) in C:\Bone\Bone\src\Actions\_Action.cs:line 394
   at Bone.Action.ToString() in C:\Bone\Bone\src\Actions\_Action.cs:line 518
   at Bone.Base.get_Content() in C:\Bone\Bone\src\Classes\Base.cs:line 80
   at ASP.skin_aspx.__Render__control1(HtmlTextWriter __w, Control parameterContainer) in c:\inetpub\dntech.gr\skin.aspx:line 315
   at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children)
   at System.Web.UI.Page.Render(HtmlTextWriter writer)
   at Bone.Asp.RenderSkin(TextWriter w) in C:\Bone\Bone\src\Classes\Asp.cs:line 71
   at Bone.ModalAction.RenderPage(TextWriter w) in C:\Bone\Bone\src\Actions\Modal.cs:line 81
   at Bone.Asp.Render(HtmlTextWriter w) in C:\Bone\Bone\src\Classes\Asp.cs:line 82
   at System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)
   at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)