Calling client function from server in on.* raises exception

[qwe2]

Calling any of the on.* methods with a quotation from the server-side causes the following exception:

System.TypeInitializationException: 
The type initializer for '.$Attr' threw an exception. ---> WebSharper.JavaScript.ClientSideOnly: This function is intended for client-side use only. 
at WebSharper.UI.Next.Client.Attr.OnAfterRender(FSharpFunc`2 callback) 
at .$Attr..cctor() --- End of inner exception stack trace --- 
at .$Attr.mk@109(FSharpList`1 acc, Address a) 
at [email protected](Info meta) 
at WebSharper.UI.Next.Attr.Write(Info meta, HtmlTextWriter w, Boolean removeDataHole) 
at [email protected](Attr a) 
at Microsoft.FSharp.Primitives.Basics.List.iter[T](FSharpFunc`2 f, FSharpList`1 x) 
at WebSharper.UI.Next.Elt.Write(Info meta, HtmlTextWriter w, FSharpOption`1 res) 
at [email protected](HtmlTextWriter tw) 
at [email protected](FSharpOption`1 doctype, FSharpOption`1 title, FSharpFunc`2 writeHead, FSharpFunc`2 writeBody, HtmlTextWriter writer) 
at [email protected](Stream stream) 
at [email protected](Task`1 obj)

This is caused by Attr.ValidateForm, which contains client-side functionality, being a top-level binding instead of a function so it gets called when the module is referenced.