Bukkit

v1.43 for MC 1.6.2, 1.7.x, 1.8.x

• Fixed: If the cost for an item of a normal player shopkeeper are between high-currency-min and high-currency-value the first slot of the recipe remained empty (and by that the trade became unavailable). We now move the low cost into the first slot in this case.
• Slightly improved handling of invalid costs (this can happen if somebody manually modifies the save file) for trading player shopkeepers: if the first item for some reason is empty we now insert the second item into the first slot in this case, for the same reasons: making the trade still usable.
  

Also please take a look at the changelogs of the versions since v1.20 for all not yet fully documented changes!

• If the trade for a written book fails players can sometimes still open and read the book if they close the shop and click the temporary fake book in their inventory fast enough. There is not much I can do about this..
• Server crashes and improper shutdowns might cause living non-citizens shopkeeper entities to duplicate sometimes.
• The 'always-show-nameplates' setting is no longer working on MC 1.8.
• Compatibility with older bukkit versions is untested. If you encounter any problems let me know and I will look into it.
• When switching from a bukkit version which support mojang uuids to a bukkit version which does not support mojang uuids yet all stored owner uuids of player shops are lost.

Also please take a look at the changelogs of the versions since v1.20 for all not yet fully documented changes!