My turret became unavailable. Hitting 5 wouldn't bring it up, mousescrolling would skip and pass over. Resupplying at a terminal didn't work. Logging to the char select screen and logging in fixed it.
Happened to me. Dying while deploying it sounds like it might have been the cause, think I was trying to deploy the turret and got shot while doing so. After that the 5th option was totally locked out, no amount of redeploying would fix it.
It just happened again yesterday, and I didn't die this time. I just dropped the turret then wanted to rop it again (before entering it) and couldn't. I then entered the turret, exited, and then I could drop it again.
Happened to me. I think it fixed itself after I changed to another class and changed back to engineer later. Still a bug.
I have this happen fairly regularly, but I die fairly often attempting to place my turret. The only fix is to log out and back in, swapping classes won't work, but you don't need to exit entirely.