I am having the same problem. I have been working in PowerPoint with a couple .pptx files. One I've been able to open, work in, save, close and open again. The other, I'm not able to open anymore. I have Office 2004 for my Mac (System Version Mac OS X 10.5.8) and am running Version 11.5.7 PowerPoint.
I just installed the newest converter, and have had no luck opening up the document. When I try, my error message reads as such: An error occurred while converting your file. To fix the problem, go online and download the converter again. If you need support, refer to error identification number -
2147483640.
Help would be greatly appreciated, I'm on a deadline for this one...ahhh.
Thanks.
Michelle