Minecraft version: 1.12.2
Wizardry version: 4.1.4
Environment: Server

Issue details:
If after using the summoning spell, the player dies, the console is written a lot of errors.

Is that the entire log? It only has the first line of the stacktrace, which isn't enough to find the problem. If you have a full crash report (rather than a console log) that would be very useful. Thanks.

There is no crash, I have only error in console. Here is full log. I summoned the Phoenix and the skeleton. After death player battle with mobs lasted. And then I have error in console.
latest.log

Must have missed this, sorry. Thanks for the log, that's much more useful. Interesting that it doesn't cause a crash though, perhaps Sponge is catching the error.