I was having this problem with a freebie cutter from Accuquilt--the Olfa blades have a notch in them and it would jam in the freebie cutter and not turn. When I replaced with a different blade that did not have those notches it solved the problem--about drove me crazy figuring it out though as have several rotary cutters and never had a blade design issue.

When putting your rotary cutter back together remember that. It should look like a cowboy hat with the brim turned up. That’s how I always remember which way is which.

There are videos on you tube that show you exactly how to put your cutter back together. If I knew your brand, I'd find one for you

Just once, really, I actually placed two blades in the cutter without realizing it. The two blades were stuck together with the oil that they are packaged with. When I found this out, I couldn't even slide the two apart, they were stuck so tight. I had to use a needle at the hole to force the two blades apart enough to get a tiny air bubble in between them.

josieh, were you able to fix this? Just asking, as I've had a similar problem recently (once again!) and came across this topic.

This, and also once I've also put the nut back on with the wrong side. Both sides are threaded, but only one side of the nut makes it fit properly.

Had this two-blades situation too, be super careful when checking to stay safe as it's so easy to cut your finger (been there, got some stitches). The oil on the blades usually makes it hard to separate them, so I used a pin to separate them.

If you are using the grey and orange Fiskars cutter, check to see if the plastic ring around the bolt is cracked. Mine cracked from either old age or use.

Contact the company. They may offer a replacement for you.