>>>Try to execute them on the separate lines

? myCollection.Remove(-1)
>>>? myCollection.Count
>>>

>>
>>Of course,
>>as it must be, the result is the same one,
>>the collection is not emptied completely.
>
>It's not always the case when dealing with bugs.

This is true, Only that I had tried that code before opening the thread.

The point is that every method of the Collection class is not reliable.

Ill-fatedly it is difficult replay with a short code,
and without a code to analyze I doubt that the VFPT can arrange it.