Ooooooooops.
Apparently the fix on 2.1.5 caused audio selection to become much slower. This release will hopefully fix all of those issues. Since this is a very minor change, you can download a RAR with only the new executable (plus its pdb) and extract it over the 2.1.5 install (typically “C:\Program Files\Aegisub”). The RAR “patch” is available here. [Exias’ mirror]
If you want to download the complete 2.1.6 installer, you can download it here. [Exias’ mirror]
Also, a cookie to the first one who can tell me what Hollywood movie is related to this particular version number. ;)