Yes, the Olympic plates. Stealth plates.
Made of metal as thin as tinfoil... far less robust that regular plates. Very prone to cracking and breaking.
What has been your fiix for these bad boys?
I was thinking a little jbweld... maybe some epoxy...
The key is to run washers in the back of it so you don't bend the area that you affix it to the bike with... but that's a bit of a moot point when you figure it out because you have a cracked plate.
These things were made low budget it seems.