I've come across a few chests (the timed ones) that I could not open.

Some people theorize either that you might already have what's contained inside but the game still spawns the container (though you can't open it.)

Or, it's a glitch that NRS will have to fix. I know I can't open the box that spawns in the Acid Falls and the one in the Spike Pits.

That's exactly the same i can't open. But i don't think i've opened them before. Because other timebased chest that i've opened before don't spawn anymore.

I'm still hoping for some super secret unlockables or something like this.

I've had no trouble opening any chest. Sorry I can't be more helpful.

I made a thread about this a while back. I found 3 that won't let you get close enough to see the price

Might be stuff for the DLC characters??

I hate all of you. I don't even know how to access the majority of the Krypt. Someone help!