Thx for the update - in which OS versions did you observe the problem ?
As Windows 10 is supposed to work similar to rolling updates with new code basis every 2 years,
chances are somewhen a similar code basis is used in Win 10 an 11, with 7 and 8.1 left out...

>I can nomore reproduce the failed selection in an installation of VFP9 in Windows 11.
>Regards,
>Georges Coppens
>
>Hi Naoto,
>hmmm, the description in the MSDN-link DOES sound a lot like your described issue.
>I'd probably use 3 pronged attack:

>1) try vfp advanced if the described fix there works, to have a fallback option
>2) dynamically widen the cbo while dropped down to the (width with scrollbar)+9 of the dropdown rectangle
>3) play with mouseup or -down forcing .click(), perhaps with wrapping cbo inside a cnt

>With 2 or 3 working you should have the option to stay at pure vfp runtimes, as problem seems to be caused by events not being triggered normally, so either fix "event receiving area" or hammer the not "evoked" (as "raise" is ambiguous in this context) events via other events ;-))
>
>If those 3 are unacceptable or not working, the big sledge hammer is to create a "picklist" based on grids - this is the approach used by vfx to get easier control via single mold:
>As you can always create a specific cursor as record source, you minimize dependency on the various different ways to feed a cbo. Downside is using internal resources, as each cursor has more impact than working off array - perf of each picklist is fine, but on heavy screen designs with hundreds of cbo working off arrays might be a better fit than havin a DS with hundreds more cursors.
>
>When working with a solid code basis as in vfx, this will make life easier when you pass the first hurdle of forgetting everything learned on cbo and give such a picklist a chance.
>
>At first I doubted the "picklist" approach a lot, but after using it in several apps I can recommend it
>pls. inform of things tried and not working, best based on the sample code from MSDN link
>
>regards
>thomas
>
>>As I stated, the combobox is pretty simple:
>>- the style setting is that for a dropdown list
>>- it is not bound to a table nor array
>>- it is populated with AddListItem() (typically in the INIT() of the form)
>>
>>One thing that I'd not ruled out yet is the possibility of an older VFP runtime library -- we'd run into this before. In this particular case I vaguely recall we did transmit an updated library install -- though the system might've been locked down (with the particular user not having admin privileges) and the install might've silently failed.
>>
>>>This problem is fully described in an other forum: https://social.msdn.microsoft.com/Forums/en-US/8702a050-8a09-4eaf-8b58-2e6a572512a8/vfp-90-combo-box-select-list-problem?forum=visualfoxprogeneral
>>>
>>>>Hi Naoto, I found a bug that may be the one you bumped into or not!
>>>>
>>>>On our VFP app here, we have this lasting bug: "when you select from a VFP combo with you pointing device (ie mouse!), it works... Except for the alas common case when the user mouse has, even very shortly, got out of the "dropped-down" part of the list".
>>>>
>>>>That's an old one! Possibly corrected by Chen. If that's the case, I'd be glad to know!
>>>>
>>>>Difficult to say it in a different way. But this is clearly a very subtle bug. You need to select straight from the list. Any lateral move with your mouse off the dropped-down list will result in a "miss": the change will not be made.
>>>>
>>>>Most users do not get into it, since they use their mouse in a "straight way". Others with a sort of a "jittering mouse hand" will discover this bug and learn to "monitor their mouse position on the combobox" more accurately.
>>>>
>>>>I have found no correction to it except to teach the users in the way to use this touchy vfp combo. That's what training sessions are for! But I'd happily follow on this thread if a solution is available!
>>>>
>>>>Daniel
>>>
>>>The mouse pointer was indeed over the listbox when the user clicked on the item. Thinking back at the situation, I've a vague recollection that I didn't observe the normal "tracking" behavior (where the selection within the listbox would "follow" the mouse pointer -- i.e. the highlighted item in the listbox would "follow" the mouse pointer)