1) Download the Reset Database Tool: https://ftp.reallusion.com/reallusionsupport/ResetDB_IC8CC4CTA5.zip
2) Close iClone 8/Character Creator 4/Cartoon Animator 5 program.
3) Uncompress the "ResetDB_IC8CC4CTA5" to local drive.
4) Double click the related .bat file to run it.
Eg: For iClone 8, use "Reset IC8 Database and Registry.bat" and so forth.
5) Wait around 30 seconds for rebuilding the database.
6) Done.