You have some(one/all) problems of the following:
* the "reshade-shaders" folder is not exist in game folder. (same location as TS4.exe and TS4_x64.exe)
* effect/texture search path is missing from settings.
If the "reshade-shaders" folder is missing in game folder, retry to install the ReShade Setup and agree to download the shaders.
Check your settings of "Effect Search Paths" and "Texture Search Paths"
If your setting is
Effect Search Paths ".\"
Texture Search Paths ".\"
overwrite to
Effect Search Paths ".\reshade-shaders\Shaders"
Texture Search Paths ".\reshade-shaders\Textures"
Restart the game after modifying.