So me and my friend made a quest map, but we didn't finish it yet. She did something wrong and now the command block doesn't let us go creative mode we can't destroy it while survival... What should we do? Is there any way to destroy that block?
Depending on what version of minecraft you made it on.. maybe you could use MCedit (AFAIK MCEdit hasn't been updated for 1.13-1.14)
Open the map up in it & go to the location of the command block (hopefully it should be close to where you left the game) then just use the program & delete the command block > save & reload the map in-game
I THINK there's a way to delete the block using something like nbtEditor but not sure - just in case you made the map in 1.13/.114