Hi @MingboPeng,
I am trying to use the Ironbug_20210329.zip file with OS 3.2 but I am still getting all those startup errors that people are complaining about.
I checked my openstudio/csharp folder and it does have all the .dll files that you mentioned in another post:
Wonder what can be done to fix this issue 
edit: it may be important to mention that I tried updating from an older version of Ironbug, but I deleted the Ironbug folder located at C:\ first as directed