The Cryolator disappears after using the Dogmeat glitch

Solution 1:

This was a reported bug, as of patch 1.34. If you used the glitch on console, and the gun glitched out, I'm afraid it's gone. If you happen to be playing on PC, you might consider using console commands to give yourself one, instead.

Bugs

• Dogmeat can no longer be ordered to get the weapon after the 1.34 update. Doing so will glitch the game and Dogmeat will either grab a pipe gun or a combat shotgun and sometimes nothing and the Cryolator will disappear. ^[verified]- "Cryolator (Fallout 4) @ Fallout Fandom

Roddy of the Frozen Peas reports that, at least as of 11/7/2020, you can't physically take Dogmeat into Vault 111. This was likely patched in to prevent both the original exploit, and the resulting glitch that occurred past patch 1.34.

Obtaining the Cryonator

• You can open the container, yourself, once you gain rank 3 in the Locksmith perk. This perk requires 4 perception, a player level of 18, and the two preceding Locksmith perks before being unlocked.
• If you have Cait as a companion, she can pick the lock. You may need to give her a number of bobby pins for her to open the lock.
• If you have the "Automatron" addon, you can upgrade robot companions with a lockpick module, which gives them the same lockpicking ability as Cait. The lockpick module requires 4 adhesive, 2 aluminium, 1 ceramic, 2 circuitry and 3 rubber and must be crafted from a robot workbench.
• If you are playing the game on PC (and not in Survival mode), you can just give yourself the gun via console commands. Press the ~ button to bring up the console, and enter the command player.addItem 00171B2B 1. This should add one Cryolator to your inventory. You will likely also need ammo, which you can add with player.additem 0018ABE2 X. Replace X with how every many cryo cells you want.