Can't place ANY lots

I have a fully ultimate-fixed copy of G4TW's TS4, which runs perfectly bar the fact that I cannot place any lots from the gallery – if I try to place directly into an empty lot from the manage world screen, the 'building lot' screen hangs indefinitely, and if I try from within an empty lot in build mode, no lot appears and the only icon on the toolbar at the bottom of the screen is a greyed-out cross/close button (where I can get back into the regular build toolbar by clicking anywhere around it). This is the case with CC lots (both tray files and package) and also with the EA lots (I tried to play both base game and Dine Out lots to no avail). Is there anything I might do to fix this? 

Thanks in advance!

lemonshiv wrote:I have a fully ultimate-fixed copy of G4TW's TS4, which runs perfectly bar the fact that I cannot place any lots from the gallery – if I try to place directly into an empty lot from the manage world screen, the 'building lot' screen hangs indefinitely, and if I try from within an empty lot in build mode, no lot appears and the only icon on the toolbar at the bottom of the screen is a greyed-out cross/close button (where I can get back into the regular build toolbar by clicking anywhere around it). This is the case with CC lots (both tray files and package) and also with the EA lots (I tried to play both base game and Dine Out lots to no avail). Is there anything I might do to fix this? 

Thanks in advance!

Hello @lemonshiv and welcome to the forum,

Have you also installed the other Games4theworld releases of The Sims 4 (DLC) too? The actual install order is the following (see also the guide).
Base game -> Get to Work -> Get together -> Ultimate fix.

I have, yes! I installed the base game > get to work > get together > ultimate fix a few months ago, and then the most recent ultimate fix on top last week. I'll try to reinstall the whole lot from the most recent files available, and see if that helps.