we just bought FPD, version 4.7.3. I install it to our website and was showing nothing in the backend, except the Designs and Settings pages. Blank screen in Products, Product builder, UI composer. 2 days i was trying the solutions. Downgrading Wordpress, Woocommerce, setting other versions of PHP etc. Nothing was working.
Today i found the solution, finally. Problem is one line in "fancy-product-designer.php". On the line 62 is in original downloaded file (from Envatomarket site) "const VERSION = '4.7.2'; " This need to be changed to current version of FPD like "const VERSION = '4.7.3'; " After this change, menus are back and working.
Hope this help to somebody, who have the same problem like we had. And please "rady cal" (owner of FPD), fix this in the downloaded files on Envatomarket (codecanyon.net) site, that other customers had not same problem.