Yes, this is also how I started to get it. If I cannot change the code what's the purpose of giving it in edit mode. I don't want ClassBrowser to apply code changes to relevant class. Just modifying some code there to use viewcode.prg as prg based class. It was readonly in VFP5 and I was copy&pasting. I think this is a kind of bug.
Cetin

>This is a copy of a response I sent to another member on 13/09/1998.
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>You may have made the same mistake I did.
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>I selected the view code button in the class browser; made a change to the displayed code and saved it.
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>The next time I tried to get into the class browser I got the invalid buffdirty call and VFP 6 shut down.
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>I looked in the VFP 6 root directory and saw a viewcode.prg and a viewcode.bak. What I had done was modify the viewcode.prg, not the class.
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>I deleted both files then went back to the class browser and it worked okay. VFP even put a "good" viewcode.prg back into the root directory so the view code button worked, also.
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>Hope this helps!
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>>could someone explain to me what is the error
>>INVALID BUFFDIRTY CALL
>>It kicks me out of the application right away.
>>Thanks
>>Armando Veo
>>Guatemala