The window size is (0, 0)

Hi there.

I also work with DevX and have found that there are some major differences you need to work around.  Here's some things I have found so far.  A combobox is actually a panel->table->cells->textbox in.  Depending on how many buttons you have in your combobox, you may have more cells, but generally the second cell(0,1) has a textbox in with cell(0,2) being the down arrow.  I have a script for each DevX control type e.g. ASPxCombobox, ASPxGrid etc with methods that take the mapped object as parameter along with say the text you want to type.  These can then be dragged straight into a KWT.   I map the Table from Object browser and use WaitXXX and FindAllChildren methods with objecttype = textbox to get the textbox. This sorts the vast majority of cases.  Your additional info seems to indicate you are clicking the outer panel rather than the textbox inside the table. You have to type stuff into this textbox.  Also, use Keys() rather than SetText().  DevX does it's work on KeyUp, so SetText won't get the dropdown to show, update the combobox values etc.  My script looks like so (copy paste and edit on the go, so may have some syntax errors):

		var waitObject = comboBoxObj.WaitCell(0,1,5000)  //Check that the combo box is ready
		
		if(!waitObject.Exists)
		{
			Log.Error("ASPxComboBox is not ready","",pmNormal,"",GetPagePicture());
			return;
		}
		
//now find the cell with the textbox in
var cellprops = ["ObjectType","RowIndex","Visible"] //exclude ones that aren't visible.  Comboboxes have a cell(0,0) with nothing in
		var cellvalues = ["Cell",0,true];	
		var cellItems = comboBoxObj.FindAllChildren(cellprops,cellvalues,2).toArray();
		if(cellItems.length==0)
		{
				Log.Error("Unable to find cell elements of Combobox table in the allocated time.","",pmNormal,"",GetPagePicture());	
				return false;
		}

		
		for(i=cellItems.length-1;i>=0;i--)
		{
				if(comboboxTextObj==null || comboboxTextObj==undefined)
				{
					comboboxTextObj = cellItems[i].FindChildEx("ObjectType","TextBox",1);					
				}	
				cellCollection.push([cellItems[i],cellItems[i].Enabled]);
		}	
		//Now make sure the Texbox is ready
		comboboxTextObj.WaitProperty('Exists', true, 10000);
		if(!comboboxTextObj.Exists)
		{
				Log.Error("Could not find Text element of ASPxComboBox","",pmNormal,"",GetPagePicture());
				return false;
		} 
//yay, you have a textbox to type in
comboboxTextObj.Click(); //no need for x,y coordinates, you can just click the textbox.  TC will click the middle
comboboxTextObj.Keys("^a");
comboboxTextObj.Keys("[BS]");
comboboxTextObj.Keys(textValue);
comboboxTextObj.Keys("[Tab]"); //DevX only "selects" an item from the list if the textbox loses focus by either clicking an item, pressing the down arrow ( comboboxTextObj.Keys("[Down]"); ) or tabbing out.
return true; 

Also, DevX has loads of Ajax, so the page might look ready but the controls arent.  You may have to add delays (yes, they make me cry) , use RefreshMappingInfo() or even both when you encounter these issues

Further, if the loading panel is on screen, TC can click on a textbox, but not type because it will get an object not available for input, as it is disabled.  You need to wait for the loading panel to disappear before you start doing any work after a page load/postback on any pages that have the loading panel on.

As tristaanogre can attest from one of my recent threads, this is a messy process.  If you read through this thread, you will find a function and some notes on how to test that the loading panel is gone, which you can call each time you try and set text.  It adds a small bit of overhead each time you set text, but is faster than a Delay which needs to cover any amount of load delay.  You could even parameterise your combobox script to take a boolean value to suppress the wait function if you know it won't show.  https://community.smartbear.com/t5/TestComplete-Functional-Web/Best-way-to-test-that-something-doesn-t-exist-without-an-error/m-p/174126#M33525 

Did I say it's messy ?