I know this is a shot in the dark but....

Is there anyone here with the knowledge/knowhow to be able to fix up this guys doom level fusion wads to become playable?

http://www.moddb.com/games/doom-compile-project/downloads

Allow me to explain. All these wads listed above are not playable except for the "Doom 1 under 1 level.Version 3" file (playable, but it lags like hell.)
http://www.moddb.com/games/doom-compile-project/downloads/doom-1-under-1-level

The reason the others are not playable is because when you start a level. You are immediately killed by an invisible demon. The original author says he doesn't know whats causing the problem or how to fix it.

I know he has posted a lot of versions of this so I am not asking someone to go out of their way and fix them all. But I would love to see these 3 fixed and in playable condition.

Doom 1 & 2 fusion
http://www.moddb.com/games/doom-compile-project/downloads/1st-attempt-at-fusing-doom12-together

Doom 2 as one continuous level
http://www.moddb.com/games/doom-compile-project/downloads/doom-2-compiled-as-one-continous-level

&
This version of Doom 1 continuous level.
http://www.moddb.com/games/doom-compile-project/downloads/doom-1-as-1-level-version-20

(Title Ozzy refrence)

Jimp Argon said:

The reason the others are not playable is because when you start a level. You are immediately killed by an invisible demon. The original author says he doesn't know whats causing the problem or how to fix it.

Heh, IIRC the author of H-Doom purposefully added this function, IF playing with Brutal Doom. You should ask Mike12/HDoomguy over at his Tumblr page.

Im sorry what?

What does H-Doom or Brutal doom have anything to do with what I posted?

Doom 2 as one continuous level, there is a proper make of it.

http://prboom-plus.sf.net/memorial.zip

Edit: The other 2, I can't find anything else more about them, than you already know.

Thanks anyways, but I was already aware of memorial.

I was wanting to play around with this guys version. (without instantly dying that is...)

Jimp Argon said:

(without instantly dying that is...)

Yea, that was weird as fuck. I could not get out of the start room of IoS. I had to die, turn on god mode and then console resurrect.

If the one invisible demon at the start is the only problem and you play with ZDoom/GZDoom you can just warp to the map you want to play with +notarget on command line, kill the demon with "mdk", use "notarget" in the console and play as normal.

The command line should look something like this:
zdoom -file filename -warp 1 +notarget

If +notarget doesn't work on the demon, try +freeze or you can just use "resurrect" in console to resurrect yourself.

But I assume there's probably more of these invisible demons in the maps...

I was hoping more that someone would have the know how / be able to patch the wad so I wouldn't have to use console commands to attempt to play these.

A "ask and you shall receive" kinda thing. I've seen it happen a few times on here already. It was worth a shot asking.;-)

Find out what his editor number is by looking into the first map in a map editor, then open all of the maps in a map editor one by one, use the "Find and Replace" feature to find all things with the specific editor number, delete them and save changes. Or, to avoid opening all maps one by one, use SLADE3's "Archive - Maintenance - Replace in maps" feature, that will take effect in all maps in the currently opened wad.

I tried the first 2 but I didn't died immediatly or got killed by invisible monsters as you said. However in the Doom 2 as continuous level you start on MAP30, and on Doom 1&2 fusion on E2M7: the author didn't removed all the unnecessary player 1 starts. There aren't custom monsters in the wads. Also like one the guys who commented on the page I wasn't able to build the nodes on Doom Builder. I don't think that the author knew exactly what he was doing that it's better if you try to do this from scratch yourself.