Item disappear on anvil and enchants are not combined

Please follow screenshots:

1. Inventory with 2 boots, put them on anvil

2. first is Fire Protection IV

3. Second is Protection III

4. Combined is expected just with single enchantment (1st one). I am expecting combination of 2 enchatements

5. Switch boots, 1st - protection III

6. Second - Fire Protection IV

7. Combined is expected just with single enchantment (1st one) I am expecting combination of 2 enchatements

8. Ok let's combine boots After clicking on expected boots - I hear anvil sound and nothing in my hand or in inventory

9. Nothing near the anvil or on the player... boots are disappeared

P.S> Previously I got the same effect with pants, so I recreate the issue with boots.

PPS> The map was created in 2015-10-14

I don't know if the below will be useful

[15:13:33] [Client thread/WARN]: Received unknown passenger for vt['Chicken'/82148, l='MpServer', x=-203.50, y=35.00, z=-34.50]
[15:13:38] [Client thread/WARN]: Received unknown passenger for vt['Chicken'/82148, l='MpServer', x=-203.50, y=35.00, z=-34.50]
[15:13:43] [Client thread/WARN]: Received unknown passenger for vt['Chicken'/82148, l='MpServer', x=-203.50, y=35.00, z=-34.50]
[15:13:48] [Client thread/WARN]: Received unknown passenger for vt['Chicken'/82148, l='MpServer', x=-203.50, y=35.00, z=-34.50]
[15:13:53] [Client thread/WARN]: Received unknown passenger for vt['Chicken'/82148, l='MpServer', x=-203.50, y=35.00, z=-34.50]
[15:13:58] [Client thread/WARN]: Received unknown passenger for vt['Chicken'/82148, l='MpServer', x=-203.50, y=35.00, z=-34.50]
[15:14:03] [Client thread/WARN]: Received unknown passenger for vt['Chicken'/82148, l='MpServer', x=-203.50, y=35.00, z=-34.50]
[15:32:29] [Server thread/INFO]: Saving and pausing game...
[15:32:29] [Server thread/INFO]: Saving chunks for level 'New Dawn (2015-10-14)'/Overworld
[15:32:29] [Server thread/INFO]: Saving chunks for level 'New Dawn (2015-10-14)'/Nether
[15:32:29] [Server thread/INFO]: Saving chunks for level 'New Dawn (2015-10-14)'/The End
java.io.IOException: Stream Closed
	at java.io.RandomAccessFile.seek0(Native Method)
	at java.io.RandomAccessFile.seek(RandomAccessFile.java:540)
	at asi.a(SourceFile:319)
	at asi.a(SourceFile:259)
	at asi$a.close(SourceFile:240)
	at java.util.zip.DeflaterOutputStream.close(DeflaterOutputStream.java:241)
	at java.io.FilterOutputStream.close(FilterOutputStream.java:159)
	at java.io.FilterOutputStream.close(FilterOutputStream.java:159)
	at ask.b(SourceFile:146)
	at ask.c(SourceFile:131)
	at baw.c(SourceFile:37)
	at baw.run(SourceFile:30)
	at java.lang.Thread.run(Thread.java:745)
[15:32:30] [Server thread/INFO]: Stopping server
[15:32:30] [Server thread/INFO]: Saving players
[15:32:30] [Server thread/INFO]: Saving worlds