Wt

From time to time I get these messages, usually with a pop-up WDialog box. I don't know what causes them. What should I be looking for in my code?

/home/developer/projects/artecams/src/Wtx/Dbo/FieldDefLookupWidget.cpp:291 on_changed(): -1
[2019-Jul-09 15:51:24.514] 27033 [/staff DcR3aEo9nbIbYavb] [error] "Wt: decodeSignal(): signal 'sd85' not exposed"
[2019-Jul-09 15:51:24.696] 27033 [/staff DcR3aEo9nbIbYavb] [error] "Wt: decodeSignal(): signal 'opwelqf.scrolled' not exposed"
[2019-Jul-09 15:51:24.696] 27033 [/staff DcR3aEo9nbIbYavb] [error] "Wt: decodeSignal(): signal 'opwelol.scrolled' not exposed"
[2019-Jul-09 15:51:24.745] 27033 [/staff DcR3aEo9nbIbYavb] [error] "Wt: decodeSignal(): signal 'opwelqf.scrolled' not exposed"
[2019-Jul-09 15:51:24.745] 27033 [/staff DcR3aEo9nbIbYavb] [error] "Wt: decodeSignal(): signal 'opwelol.scrolled' not exposed"
[2019-Jul-09 15:51:24.746] 27033 [/staff DcR3aEo9nbIbYavb] [error] "Wt: decodeSignal(): signal 'opwelqf.scrolled' not exposed"
[2019-Jul-09 15:51:24.746] 27033 [/staff DcR3aEo9nbIbYavb] [error] "Wt: decodeSignal(): signal 'opwelol.scrolled' not exposed"

This would be how I might typically pop-up a dialog window. I plop a handful of controls and things. And, then, for some reason one dialog window will spit dozens of these error messages, and others do not, and I'm not sure what I should be looking for since I pretty much open my dialog windows the same way all over the place.

   289        m_targetID = provider()-> find_id( value );
   290  
   291        std::cout << __FILE__ << ":" << __LINE__ << " " << __FUNCTION__ << "(): " << m_targetID << std::endl;
   292  
   293        if( m_targetID < 1 )
   294        {
   295          auto dialog = addChild( std::make_unique<Wt::WDialog>("item picker") );
   296          dialog-> rejectWhenEscapePressed(true);
   297          dialog-> show();
   298          auto cw = dialog-> contents()-> addNew<Wt::WContainerWidget>();
   299          auto lw = std::make_unique<Wt::WVBoxLayout>();
   300  
   301          auto u_search = std::make_unique<Wt::WLineEdit>(value);
   302          auto search = u_search.get();
   303          search-> setDisabled(true);
   304          lw-> addWidget( std::move( u_search ) );
   305  ...

I'm just not sure what to do with that error message.