Here is the string I was given:
All I know about this puzzle (after asking the people who created it) is that there's a key that will either solve or help solve the puzzle.
I've tried all kinds of stuff to get something coherent to show up. I did a frequency analysis and tried different combinations of those letter matches (e.g. "E" is most frequent in the string, so I plugged in "E" to the cipher per ETNORIA, and so on). It does appear to be natural language based on the frequency analysis, but none of the substitutions I was making seemed to get me anywhere.
The double letters are throwing me off too. There are only so many likely double letter combinations, and the fact that the double-W starts the cipher is hard to work with. It could be a word like OOPS, but that seems an odd way to start the string. I thought maybe the double letters indicated something else like a space, or that they should be ignored all together, but that didn't get me too far.
I also looked at the most common trigrams and digrams. HNE and ORE repeat twice each so I tried using THE as one of those. I didn't really have anywhere to go from there. TE repeats 4 times and NE repeats 3 times.
Not having spaces is really making this difficult. This is part of a series of puzzles they've had sitting around my office, and they've gotten progressively harder. Based on the last one I solved, it's possible this one goes multiple levels deep, such as revealing another puzzle after solving the cipher.
You don't necessarily have to solve this for me, but I could really use some more tips!