yes, %AppData%\Micro…Flightsim… We have some topics about, newest example I remember I need help, the simulator crashes after the New Zealand Update - #24 by MichaMMA ( in following posts are also more detailed infos ).
what exactly ? This file is for starting plugins ( simconnect ), etc.
But as mentioned, first try the cleanup ( and dont forget the windows hosts file, if the mentioned add-on was installed ). If that will not help, add some additional informations in the post, may most important the error message which you can find within the windows event log. Also its allways important to distinct “ctd while startup - vs - ctc while start a flight - vs - ctd in a flight”. If the issue while “startup” is gone, there are topics with possible reasons for the other situations.