Bukkit

What steps will reproduce the problem?
1. Create a shield with a design on it (apply a banner to a shield)
2. Do something that makes multiinv switch inventories (in my case, switch from gamemode 0 to gamemode 1)
3. Shutdown the server and restart it, rejoin the server
4. Do something that makes multiinv restore the original inventory (in my case, switch back to gm 0)

What is the expected output? What do you see instead?

I expect to have the shield back with the design.  Instead, I get a shield with no design.

Have you tried the latest version of MultiInv from http://build.yu8.me:8080/job/MultiInv3/ (If not please try it to see if it solves your issues)?
I am using version 3.3.6.  The release on that site doesn't have changes past March 2, and version 3.3.6 was released after that, so I assume 3.3.6 is current.  If that's not the case let me know and I'll retest.

What version of the product are you using (if you say "latest" you will NOT be helped)? 3.3.6

Confirmed using build #72 (Wed Mar 02 03:26:19 UTC 2016) and Spigot MC-1.9 2016-03-31 BuildTools 50

Happens both when in Surivival (default) world and in additional worlds..

@spetznack: Go

Yep, haven't gotten around to saving those properties quite yet.

@Tux2: Go

Has there been any fix for this yet?

This might be of some help. https://www.spigotmc.org/threads/how-to-set-shield-design.127794/page-2