ERROR: AV's and IWButton.picture.data: the parameter is incorrect

[MJS@mjs.us]

I have an IW app which is a map tile server that creates tiles (via bitmap then to png) if they do not already exist using threads.  UserSession thread should be equivalent in your case.

Below is a sample locking / unlocking a bitmap while editing and should eliminate collisions. 

Code:

try {
  try {

    ...
    if(!bmp->Canvas->TryLock()) { LogError("BMP TryLock failed."); return; }
    ...
    //SAMPLE BMP MANIPULATION
    ...
    bmp->Canvas->CopyMode = cmSrcCopy;
    bmp->Canvas->CopyRect(Types::TRect(0,0,IDIM,IDIM),bmp_odim->Canvas,Types::TRect((ODIM-IDIM)/2,(ODIM-IDIM)/2,((ODIM-IDIM)/2)+IDIM,((ODIM-IDIM)/2)+IDIM));
    //END SAMPLE
    ...

  } catch (Exception &e) {
    LogError("RenderToCanvas:  "+e.Message);
  }
} __finally {
  if(bmp->Canvas->LockCount) bmp->Canvas->Unlock();
}

Regards,
Mark