I have tried multiple versions of Silent Gems (and lib). I keep getting a nullpointer for a missing enchantment. I was getting this with both the most recent version of tinker's and the 10/22 release (had to backdate it for Tinker's Defense to work). Here is the current log file with TiCon v2.5.6b, SilentLib 1.1.0, Silent Gems 2.1.5. I have also tried using versions 2.3.8 and 2.2.5 which are also attached.
crash-2017-04-19_02.18.02-client.txt [2.2.5]
crash-2017-04-19_01.52.49-client.txt [2.3.8]
crash-2017-04-19_02.22.11-client.txt [2.1.5]

Modlist:
modlist.txt

Please provide a log file as well (use latest versions of Gems/Lib). This crash is caused by an enchantment from another mod, so I would like to track it down.

Here is the full log file with just ArdentCraft's 4.2.02 build and the latest Gems/Lib/Extra
latest.log.txt

Sorry it took so long to get the log file for you.

Thanks. Looks like the log doesn't have the info I need though, I guess it's crashing earlier than that. I was able to replicate the crash, so I'll see what I can work out.

Crash is caused by another mod overwriting the Sharpness enchantment (others may be affected, but can't tell at the moment). At this time, I can't say what mod is responsible. I can prevent the crash, but at worst all the "modified" enchantments will be uncraftable.
(edit) Seems to be "Good ol' PvP". I recall that mod causing some issues in the past.

Can you confirm if this has been fixed in Gems 2.3.11, whenever you have time?