Hi again,

a new test confirms your problem. But why do you need to open both the .prg and the .bak at the same time? Over the more than 30 years I have programmed, I have never needed to do that, but I have a lot of duplicated code in different temp directories.

>>I can NOT copy this, Fabio, everything works as expected. Have you marked "Make backup" in Tools-options-IDE? I have.
>
>Of course ! Otherwise, who creates the .bak ?
>
>>
>>>VFP 9 can write large prg files.
>>>Now, because, at the same time, i cannot open two or more program.prg edit windows,
>>>i try this:
>>>open the program.bak in read mode, and edit program.prg.
>>>One ugly surprise:
>>>when i save (only save!!!) VFP says to me:
>>>- File access is denied (Error 1705)
>>>and
>>>- close the edit window, losing all my modifications !!
>>>
>>>To use VFP within a Dev Team ?
>>>Example:
>>>

>>>- Dev1 open a .prg
>>>- Dev2 cannot open .prg
>>>-   then Dev2 open the .bak
>>>- Dev1 works for 2 hours
>>>- Dev1 a coffee wants drink,
>>>   then it press Save
>>>- Dev1 the coffee does not drink more,
>>>   but one is drunk camomile!
>>>

>>>
>>>An optimal way in order to pass the days!
>>>
>>>Ask: why VFP open a prg in pessimistic lock mode ?
>>>Expected:
>>>

>>>- Open a .prg
>>>- At first edit operation:
>>>a) refresh the file with a write lock access
>>>
>>>b) when save, if a error occurs, NOT CLOSE THE MODIFY WINDOW !!!!!!!!!
>>>

>>>
>>>Another point:
>>>the situation is still worse than how much it seems.
>>>If you uses:
>>>

>>>MODIFY COMMAND SOMEPROGRAM.BAK NOEDIT && Read only mode
>>>

>>>VFP open SOMEPROGRAM.BAK with a write exclusive access !,
>>>and you still must to drink camomile.
>>>
>>>Fabio