Hi muzzie1993,
Yes i'm having this error message too even with Eco Lifestyle pack installed on PC.
The Sims will automatically have negative moodlet with a passer-by. Happens as what you describe.
I guess this has to do with the latest patch.
Below are my details:
Product: The Sims 4
Platform:PC
Which language are you playing the game in? English
How often does the bug occur? Occasionally (10% - 49%)
What is your current game version number? 1.62.134.1020
What expansions, game packs, and stuff packs do you have installed? All of them except Moschino, Toddler, Luxury Party and Spooky Stuff Packs
Steps: How can we find the bug ourselves? A playable Sim in your household will have automatic negative moodlet with random passer-by without any interaction
What happens when the bug occurs? Your Sim will have negative relationship with the said passer-by
What do you expect to see? No negative moodlet with any passer-by
Have you installed any customization with the game, e.g. Custom Content or Mods? No
Did this issue appear after a specific patch or change you made to your system? After the June 2020 update
Please describe the patch or change you made. Na