3.3.1. Project File Best Practices
Avoid manually editing Intel® Quartus® Prime data files, such as the Intel® Quartus® Prime Project File (.qpf), Intel® Quartus® Prime Settings File (.qsf), Quartus IP File (.ip), or Platform Designer System File (.qsys). Syntax errors in these files cause errors during compilation. For example, the software may ignore improperly formatted settings and assignments.
Do not compile multiple projects into the same directory. Instead, use a separate directory for each project.
By default, the Intel® Quartus® Prime software saves all project output files, such as Text-Format Report Files (.rpt), in the project directory. If you want to change the location of output files, instead of manually moving project output files, click Assignments > Settings > Compilation Process Settings, and specify the Save project output files in specified directory option.