Sometimes when upgrading a Delphi project to a new version of Foxit Quick PDF Library you may encounter an error message like this:
Unit QuickPDFxxxx was compiled with a different version…
The most likely cause of this error is that you may have an older version of the Foxit Quick PDF library in your project file somewhere. You need to make sure there is only one reference to the SDK anywhere in your Delphi settings. So to resolve this issue look for QuickPDFxxxx or FoxitPDFLibraryxxxx references or directories.