I wouldn’t doubt that this topic may have already been discussed earlier when Forge released, but it recently happened to me and I don’t know if there is a way to fix it or if I would just have to basically start over—
I was making a forge map and I had grouped together between 25-40 objects shaped like a base. I wanted to copy the base and bring it over to the opposite side of the map, and when I copied the grouped object, my Halo completely crashed on me, and when I went back into the forge map, I could not select the grouped objects. At all. I could grab any other item that was already on the map, but when I would hover over any piece of the grouped object, the little Hand reticule would fade through, and the name(s) of the grouped object would not appear. I couldn’t do anything.
It’s pretty lousy, and to add to that I found a flaw in the grouped objects that I didn’t catch and now I can’t fix that flaw. 
On one of my maps I have two man cannons that I cannot select, even by spawning in another one and selecting all to delete. Need a solution to this because this breaks the map.
This just happened to me. I had 11 small groups. I attempted to group 20 objects and to copy and translate them to another area. they basically began to rotate on their own and when I let go of them were all over the map. So I chose to exit Forge without making any saves. When I reloaded the file, the group count registered as 0/128 and none of the objects previously grouped are selectable. Hours of work don the drain. Shut down Xbox and reloaded everything to the same problem.
If this is going to be the tool, then I will retire to another game. This makes me sick to my stomach.
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> This just happened to me. I had 11 small groups. I attempted to group 20 objects and to copy and translate them to another area. they basically began to rotate on their own and when I let go of them were all over the map. So I chose to exit Forge without making any saves. When I reloaded the file, the group count registered as 0/128 and none of the objects previously grouped are selectable. Hours of work don the drain. Shut down Xbox and reloaded everything to the same problem.
>
> If this is going to be the tool, then I will retire to another game. This makes me sick to my stomach.
Create another group. All other groups will now be selected. Ungroup all of them, then regroup them again by hand.
I understand your pain, I have had a similar issue, where I duplicated a group and it duplicated manifold, crashing the game and giving me huge frame rate drops when I looked at these groups after reloading. Very frustrating. I am afraid you will have to restart… I never found a solution. I always try to ungroup stuff I’m done with to avoid such issues
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> > 2533274812851374;4:
> > This just happened to me. I had 11 small groups. I attempted to group 20 objects and to copy and translate them to another area. they basically began to rotate on their own and when I let go of them were all over the map. So I chose to exit Forge without making any saves. When I reloaded the file, the group count registered as 0/128 and none of the objects previously grouped are selectable. Hours of work don the drain. Shut down Xbox and reloaded everything to the same problem.
> >
> > If this is going to be the tool, then I will retire to another game. This makes me sick to my stomach.
>
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> Create another group. All other groups will now be selected. Ungroup all of them, then regroup them again by hand.
What he said. New group will select all existing groups that you can’t select manually. It sucks, but at least you don’t have to rebuild everything.
Quick tip. Never delete vehicles that are in groups then save the game. Then there’s nothing that can help you.