I already tried the ways to fix this by restart the Pageant, remove the key, re add the key, redownload the key, restart my PC and still this issue come up! After one centuries, I found the solution of this issue.
If you experienced this exhibit: PuTTY Fatal Error; when accessing the server. You may try to download the the latest PuTTY itself and update your PuTTY in this URL: https://www.chiark.greenend.org.uk/~sgtatham/putty/latest.html then your problem will be fixed.