Well, then you need to contact the maker of that installer. Is that by any chance the infamous (in this forum) installer called Softaculous? They have their own site with a link for support. Most of the people here are of do-it-yourself type, see Installing_Moodle, which works brilliantly thanks to the Free and Open Source Software (FOSS). Moodle is one, there is a whole software stack, or better stacks, called LAMP, LEMP, etc., which are also FOSS. Unfortunately Windows is closed source. No way of finding out what is happening inside.
P.S. I see, you are riding somebody else's discussion https://moodle.org/mod/forum/discuss.php?d=470030#p1886846. Hint to the moderator: Needs to be split. Maybe a subject line like, "After upgrade from 3.8.1 to 3.9, from 3.9 to 4.1.4 and from 4.1.2 to 4.5.1, a problem with dedicated forms and themes. (Windows Server)" would be more suitable. Need to add that, how you went back from 4.1.4 to 4.1.2 is a puzzle to me.