A few considerations…
- The database changed between 4.0.0 and 4.0.1.
- The versions between 2.4.0 and 4.3.4 are gone from the desktop versions download and release notes page: Desktop and OS Downloads + Manuals | Engine DJ. They are still in the Engine OS downloads page. Have I short-circuited and those are located elsewhere?
- There is this in 4.3.4 “Fixed a security vulnerability identified in the Engine Remote Library; we highly recommend that all users upgrade.”