Getting error, cannot pick up factory, too many factories picked up at once, please dome down before you pick up more. I don't have any in my inventory, but robots probably do.

actually; no, I don't have any in my robots either. =( they are stuck; I'm clearing them out; then I'll just remove the mod re-add it to get the problem to go away; unless you want me to hold onto them for logs or something for now??

The error message says what you should do. It doesn't only count the picked-up factories in your inventory, it counts all factories you ever picked up and didn't place down again.

So I have to build more factories just to put them down just to pick them back up?

I don't have any in my inventory to put down; so I literally would have to build more to do that

but no worries; like I said, I'm just going to remove the mod; it will remove all the factories; so it will wipe the problem I'm having out; just wanted to point it out and give you a chance to see something before I wiped it, but it appears as though this was done on purpose; so I'll just go back to wiping out the factories so I can clear the mod.

What? No, what could even be the point of placing new factory buildings?

You need to reuse your old used factory buildings, not delete them or throw them in a chest to rot. That error message only shows up when there are 90 old factory buildings of a single type that you deconstructed without placing them back down again. Deleting the items does not count.

I think what he means is that he may have died at some point and lost those existing factories. Hence, a bug. He has no factories to put down, but the game is telling him to put more down. I'll test this shortly and get back to you.

There's the/give-lost-factory-buildings command you can use to get those back. The command is there just for situations like this.