Someone may have already brought this up, but it says 1.3d in the mega download, not 1.4d. Also when I use the mod, then try to have sex I end up having a office screen with no options.
Viewing post in Expanded Sex Mod (for Strive 1.0d)
Chances are high that you either have conflicting versions or mods. There isn't enough info to know for certain. The current version of this mod(1.3d in files) should be used with v1.0d of Strive(the current version out despite text to the contrary).
Also, I recommend checking the godot log file in the appdata(".../Strive/logs/godot.txt") for errors after the game closes, as that may clarify the problem. The last 8 lines will probably just be the game closing. If the log is empty(happens if game crashes), you might try the debug mod to enable the 2nd window which reports errors.
Oops, the "1.4d" was a typo and never even existed. 1.3d is the most recent version and compatible with Strive 1.0d. I've now updated the description.
As to know what is going wrong, like Ank said we will need information from the logs, but my guess would either be you don't have the latest version of Strive or there are conflicing mods. Unfortunately pretty much most of the mods conflict with each other.