Hello,
Just experienced a crash with Quark, Zeta, and Expanded Combat on a singleplayer instance with a vanilla bow.

The crash log is below, it mentions an issue with listener events from Quark/Zeta.

https://mclo.gs/Op5x3Sw

This actually appears to be a crash with the "skilltree" mod, which has its own Quiver item that is being erroneously picked up by Expanded Combat, as seen here:

Caused by: java.lang.ClassCastException: class daripher.skilltree.item.quiver.ArmoredQuiverItem cannot be cast to class com.userofbricks.expanded_combat.item.ECQuiverItem (daripher.skilltree.item.quiver.ArmoredQuiverItem is in module [email protected] of loader 'TRANSFORMER' @a7ae340; com.userofbricks.expanded_combat.item.ECQuiverItem is in module [email protected] of loader 'TRANSFORMER' @a7ae340)

(line 43 of your log)

Quark just happens to call that code, so it's shown in the log, but any other mod querying your arrows would also crash in this scenario.