Too many light styles on a face
I've tried some of the other models they don't really alleviate the problem.
Bump: Added the toxic slime into my map and there is now only one occurrence of this issue: The face of the slime directly underneath the laser catcher. The laser catcher must have something to do with the problem.
Edit: Maybe not. I removed the laser catcher and the problem still occurs in exactly the same place.
Second edit: Definitely something to do with the laser field. I covered the laser field with a nodraw block and the problem went away
Mevious, I learnt that from Tophattwaffle and I'm sure I'm right. Please read this and go to the final epigraph called "Limits". I'd say that your example means 2 light styles...
I'm inclined to go with Mevious on this one, as I used four different colours of light in the second chamber of Double Bill and only got this error when I tried to make a second set switchable...
My maps: Double Bill / Jam / Oval Window / Gymnasium / Gymnasium Part 2 / Minimalism (collection) / Resolution
All feedback welcome!
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Well El, I'll have to do some tests because it's not only Mevious, but also BEARD! who say so... I might be wrong... I respect much both guys opinions, so... 
useful tools and stuff here on TWP 
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That article from TopHATTwaffle looks very useful, but the bit about different colours creating different light styles is absolutely wrong, at least for Source. (It may have been true for Quake 2; not entirely sure.)
A lightmap has full RGB values at each sample point, so you can mix colours any way you want. (The brightness value of the light source is only used by VRAD, and integrated into the final RGB values after the lighting calculation is complete.)
The light style limit only comes into play when you're dealing with lighting that changes during the course of the game. This can either be a light that blinks or pulsates in some way, or one that can be switched on or off by the game logic. Some of the standard dropper instances have two different switching lights inside, and when you place a few of these relatively close together (i.e. in the same room), you'll have a high chance of going over this light style limit.
(By the way, Jose, don't feel bad about being misinformed on this; I'm under the impression that this is one of the les well understood parts of the Source engine.
The rest of that article looks very useful, so I'm adding it to my Portal bookmarks 
)
Other Portal 2 maps: Medusa Glare
Portal 1 maps: Try Anything Twice | Manic Mechanic
Thank you my friend, I was definitely wrong 
I apologize for posting misinformation, that was completely out of my intentions, I only wanted to help and thought I could.
This kindness is what makes you that big. Thanks again
(Yeah I loved that article by TopHattWaffle when I discovered it, it's sooo useful!)
useful tools and stuff here on TWP [spoiler]
[/spoiler]You can't have been completely wrong because removing the lights from the cube droppers did clean up the majority of those errors in my map, and I didn't have loads of them in my map either. The last one is being caused by my laser field but it doesn't seem to make much difference so I'm inclined to ignore it.
You could also try using dynamic lights instead of normal as well.
I think it just has to do with named lights - in every map I make I have a cube dropper usually near a wall, and I have my light strips. my light strip's light isn't named, and doesn't do anything but light up the room, and I never get the too many light style error. I don't even get it when my lights are flashy and near a cube dropper...
As I said there are no named lights in my map
And is there anything specific I need to do to change the lights and make them dynamic?