Window > Developer Tools > Modules not found

This window usally was not avable in laucher build of UE4, but i checked and it is now there in Windows build. So it might be related, you could raport this as a bug

In mean while you can use module command in console that shares the same function, you use that command in output log

module list - list the modules

module load modulename - loads module

module unload modulename - unloads module