sims 3 there was an error during startup please see the log for more details

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.