The cover for the paper filter attached by the CVT oil cooler has a thin o-ring that I accidently cut when re-installing the cover for the first time on my daughter's 2015 DE while doing a fluid and filter change. I made quite a mess as about 2 qts of CVT fluid spewed out of the cover when I started the car and proceeded to shift through P-R-N-D-B at five second intervals per the (Nissan) service manual. I really should've started the car and immediately checked for a leak but I've never had a engine oil filter leak on me - I still do check each time though.
I chose to try re-installing the cover for the paper filter blindly instead removing the splash shield in the driver's side front wheelhouse to be able to clearly see what I was doing. I still can't understand how I cut the o-ring but somehow I did.
I ended up going to Autozone, which had an assortment pack of o-rings for distributors. The pack had an o-ring slightly thicker than the OEM o-ring. It was difficult to get the cover to fit with the new thicker o-ring but it did finally fit. I installed the cover blindly again as I was running out of daylight and wanted to give the car back to my daughter. I was a bit more careful to keep the cover centered over the paper filter this time and as of today there are no leaks after 75 miles of combined city and highway driving.
The next time I replace the paper filter I will probably just do the extra work and remove the front wheel and the splash shield so I will be able to see what I'm doing. I'm also going to have a spare o-ring in case I tear another one. I don't want to make the same mistake again.