Re: Latest update has messed my Sims 4 game up.

@mikrolactaki3

If you have disabled Windows Defender completely, it will not interfere with running applications. It seems that turning it off in Task Manager hurt the game because when you turned it on for the first time it worked fine. Sometimes the gallery loads very slowly and it just depends on two things. first, the speed of your internet. This speed will change depending on how busy the network is. It also depends on the number of players in the Gallery. When the server is overloaded it will take ages.

Have a look here. All gallery related issues and working solutions are collected in this topic
https://answers.ea.com/t5/General-Discussion-Feedback/READ-FIRST-Status-of-the-Gallery-SCHEDULED-MAINTENANCE/td-p/9514109/jump-to/first-unread-message

Edit :

@mikrolactaki3 

This is a bit of a blind shot, but make sure the version number of the game you have on the screen on the first page at the bottom when you open the game is the same as in the GameVersion file in your game folder.
If it isn't you need to change the one in the game folder manually to make it identical to the one in the open game.

However probably Avast is still blocking it. Disable it and check Gallery without it. 

@kreatora turning off Avast, the gallery works. With Avast on, doesn't.

But gallery fails to load both ways, but not all the time with Avast disabled. Only when enabled.

EDIT 1: I have checked the GameVersion file and it's the same as the one in my game! 🙂

EDIT 2: I checked the Windows Defender process on my task manager, and it does not exist. Which means Windows Defender has been completely disabled from my PC!

EDIT 3: I have tried adding TS4_x64 and TS4_LE.exe (if I got the .exe file right) to my exclusions, still the same result.

But, coming to an end, I had a similar problem on my laptop, and I fixed it by updating my OS to the latest version, which is version 2004. Now I no longer need to disable my antivirus to get my thumbnails working - it's all okay! 🙂