Felix Griffin's Editor Mod (FGEMOD)
Well now that I went there to make that folder I found a folder called "instances_hmw"
would that be it? I was just gonna make a new folder anyways, but I don't want to mess anything up :p
So, then, is it the "instance_hmw" folder, or do I make a new one called hmw? Thanks
Okay.
I'm sorry man, but I might sound like an idiot...
I got real excited thinking how awesome it will be to get Portal 2 back and all...so, I thought "Gee, this instances_hmw folder has a gadgets folder in it, so it would make sense that I put it in there!" Yup....that was pretty dumb. So I replaced the new file with the old file (it asked me if I wanted to). So now portal 2 won't open...
Haha sorry, I really should've just waited for you to respond, I guess I was just real excited :/
So what should I do now? According to Windows I replaced the file...
Does it crash as soon as the VALVe logo video finishes?
Try running the FGEMOD again, see if that fixes it.
After the VALVe Logo (and it saying powered by source), there is a picture of P-body (and Atlas in the background) right before the main menu would come up. It crashes there.
After checking that I opened up the FGEMOD window. I selected a couple of random things. But I'm forgot how to save what I selected. After I selected some things I closed it and an error message from windows came up saying something along the lines of "the memory could not be read"...
I tried Opening Portal 2 again and the same thing happened as before.
Ah, that's the problem. My "do you want to save?" thing is broken. It's fixed in the BEE2.
Press the F1 key to save and quit. Then restart Portal 2.
Okay! 
Thank you! Portal 2 will work again--so we've got that down. Also, the new test elements came into the puzzle maker. So I built a small level to try them out. Sadly though, when I built it, it again said "There was an error building the puzzle. : /
But we're getting there!
That's probably the Sendificator problem again. Take the file "sendtor_manager.vmf" from the Sendificate source and copy it to instances/hmw/gadgets.
So, what I just did was I went to the download you gave me earlier. Then I found the sendtor_manager.vmf file. I then went back into Portal 2sdk_contentinstances
In there was a folder called instances_hmw
Instead of putting it in there, I created a new folder (inside of instances) called hmw
Inside that folder I again created a new folder, this time called gadgets. After that, I brought the sendtor_manager.vmf file into the gadgets folder. Thus, it was in instanceshmwGadgets
However, I am still experiencing the same problem :/
(Does it have to do with the fact that earlier I replaced the sendtor_manager.vmf file with some other one in:
"sdk_contentinstancesinstances_hmwgadgets"?
Thanks 
Hm...no, it sounds like you did it perfectly.
Can you go into sdk_content/maps and look at the end of your preview.log file? It'll say the exact error in there.