Hate to say, but you may have to wait for a hotfix or a new patch to use them again; use other gear in the meantime if possible. You are not the only one reporting/ having this issue. As good of a patch as this is so far, it also jacked up a lot of shit.

A lot of people are complaining about this. It seems like CDPR have dropped the ball on trying to address the game's difficulty curve. Oh dear!

I had the same problem with master feline gear. Even the quest was the same. I'm just glad there was not a single monster around or I would have to beat it with my fists. Plenty of steel swords lying on the ground and you can complete the quest with lower buffs, but it was unpleasant surprise...

Not just Feline gear.

My ENHANCED Griffin Silver Sword had its level requirement increased to Level 18 (previous to 1.0.7 it was 14).

Fotunately, I had it equiped prior to the 1.0.7 patch, so I can still use it. AS LONG AS I NEVER UN-EQUIP IT I should be OK. Fingers-crossed the game doesn't forceably un-equip it from me.

Happened to me as well with the Ursine gear. Not really a big deal for me since I was only one level away to meet the requirements.

I have the same issue with my full set of Enhanced Grffin gear. I am level 16 and they now all have a level 18 requirement. I was doing the Broken Flowers quest in the main story line, and a part of that quest forces you to change out of your armor and swap out your swords for a wooden one in order to spar. After the conversation when he went to put his witcher gear back on he could not re-equip it. He is now without equippable swords, chest armor, and gloves. He did not take off his pants and boots for the sparring at least.

I do not want to be bothered to remake another set of armor, so I think I will put the main storyline on hold even further and do a few side quests to level to 18 (if I have enough availabe). Hopefuly the changed level requirements was not intentional and that they will get a hotfix or a workaround or someothing for this.

WARNING: do not go to a Barber
The cutscene where you sit in the chair shirtless will remove your weapons and at least some of your armor and you won't be able to re-equip because of the changes to minimum level requirements.

I noticed it killed a variety of armor recipies available...So now I can't craft human gear becasue I can't get recipies for it. I can't wear stupid Gryphon armor early in game since the requirements are higher now...Not that I complaint...it is just boring now in the equipement department :P

Thanks guys, I guess I'll wait for a hotfix then. I dont have any "spare swords" on me at the moment and I dont want to waste money on equipment I wont be needing anymore in a week or so... I see why they wanted to re-balance stuff, but it would have been great if the new balancing only applied to new playthroughs.
If anyone from CDPR reads this:

I really appreciate your work and I know that developing, improving and patching software can be a pain in the ass, I just hope that you can fix this issue.
Thanks in advance!

I had the same problem but there is a very easy way to solve this. Do a rollback to version 1.06, equip your gear then update to version 1.07.

My first play through on patch 1.05 enhanced feline swords where level 23 armor was level 25

They aligned the lvl requirement for all base game school equipment to that of the wolf school DLC.

It's 99,9999999% intended.
They probably just didn't think it could have this kind of consequence, or didn't care.

well, its a pretty huge consequence. imo this kind of thing shouldve waited for the expansion packs.

i got very lucky as im also using enhanced cat school but happened to be lvl 23. had no idea this wouldve been an issue otherwise, that is maddening.

How do you think why a lots of ppl complane about stuff leveling? Because they usually walking around naked and bare handed, wearing armor and pickup swords only after battle start? :)