@Babuchas: Have you checked whether you have a conflicting mod installed? That mod is really simple, I cannot see how it could not work if you don't have a mod conflict.
@itsdorkney: I cannot check that at the moment. I got a "new" PC (in fact it's second hand, but it has a completely different system as I am used to) and atm, I don't have my modding programs working again yet. I cannot even properly look into my existing files at the time being and I have no idea when I'll be able to spare some time to get into it.
That being said, I'm getting date calls in my save on a regular basis without issues, so maybe you could share your save file + additional info which household it happens in for you. It might be possible that you don't have any eligible Sims for a date request in your game and that's why you get that LE, but that is merely a wild guess at the moment.
I assume you already made sure you downloaded the latest version of the mod (it has last been updated on March 27th)?
You could also just remove the dates and goodreputation modules of the mod for now to avoid the LEs in the meantime. If you then get date calls from Sims that are already in a relationship with another Sim, that might be an indication that my mod was blocking these Sims from bothering yours with date requests.