I have been having the same problem so I tried vladymiria's solution - it didn't work ☹️
After that I just went into "the sims 3" folder (not the copy folder)
> Computer > OS ( C: ) > Program Files > Origin Games > The Sims 3 > Game > Bin
Found the TS3.ex_ and simply changed that to TS3.exe (it prompts telling you if you change the file name it may not work correctly, do you still want to change?) Say yes....of course. The icon changes - double click and it worked.
I won't have a chance to play until tomorrow so I don't know if there are any glitches, I'll let you know.
my file was already named TS3.exe and I am getting the same error message.
i had this same problem, no solutions worked. then i discovered the problem is in the registry! the base game entry in the registry is pointing to the wrong location! i also recommend you note down the location that it thinks its in becuz your update files will probably be there and you'll have to move them manually!
i think the update patcher does this if your game is installed anywhere other than the default location which is C:\Program Files (x86)\Electronic Arts\Sims 3 if i remember correctly
incase you dont know or forgot
What am I supposed to do after I expand these folders in the registry?
