This is a ticket from one of the players on my server. I'm running 9.0.0 on 1.2.5:

I had an incident were I placed a Diamond Block and it disappeared. It was near another field, which sadly I couldn't tell there was. A notice came on and said
that I couldn't place the block there because a field was near. I didn't receive the block back.

I spoke to a4igeek and he tried to help me but there wasn't much he could as there was no proof my block had disappeared. Biting my loses I went to the mall and accidentally bought a Cake and the Diamond Block appeared.

I let a4igeek know and he suggested I let you know of the glitch through here.

I hope you can find a fix. If not it may best to let Players know if the glitch.

That's very weird, especially the part where the block reappeared, thank you for the report.