When running 3.9, under the Tools menu there is an entry that will Open the Modules Folder. Click that and you will see where the modules need to be, in their respective folders, for 3.9. The odd thing is the 3.7 modules should already be there because they use the same folder.
Open the Commentaries folder and let me know how many files are in there. If there are only 6 (3 .cmt and 3 .idx) then the 3.7 folders are not there. If around 20-30 files then they are.
Also, go to Preferences/Manage Library and be sure all the Commentary modules are checked.
Let me know how many modules are in the commentary folder.
Developer, Bible Analyzer
But to him that worketh not, but believeth on him that justifieth the ungodly, his faith is counted for righteousness. (Rom 4:5 AV)