I repeated all your steps under VFP8SP1 a few times and didn't get any errors.

>1. Create a report, any report. Even one which is empty will suffice.
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>2. Create a Modal Form, with a button. In the button click event, issue a Modify Report for the report you created in Step 1.
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>3. When the report comes up, click the report toolbar and add some text.
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>4. Now click on the calling form (outside the rerport preview window area)
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>5. The report will prompt you if you want to save changes. If you press yes, you will get a Report File is Invalid error message. All the time. VFP 7 & 8
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>7. If you open the report frx file as a table, you'll notice a record where the Expr column is empty, and the timestamp and the objcode columns having a value of zero. If you delete this record AND pack the frx table, the report is once again usable. OR if add text to the Expr column it opens again.
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>Ideas/Opinions?