It could have got too cold or didn't have enough solvents to keep it in soultion. I would warm it back up like others have said, if it keeps crashing there are other steps you can take like I adding sterile oil or a little more ba/bb. If heating it does the trick before you inject I would still run the barrel of the syringe under hot water for 10-15 seconds after you have pulled it in to the syringe and recapped the needle obviously. I do this with all my injections and it helps the oil spread more easily (viscosity) and gives a smoother injection that which should also help it not crash after it has been injected cause that can cause some pain for sure
