CRISPR may cause many mutations:

https://www.sciencealert.com/crispr-editing-causes-frequent-extensive-mutations-genetic-damage-target-deletion-site?perpetual=yes&limitstart=1

It seems there is a lot more work to do with CRISPR before it can reliably reverse genetic damage like that causing sickle cell disease.

This is one of my major objections to the commercialization of this technology. All new technologies have their problems and CRISPR (which is a lot better than previous versions of genetic tinkering) has its problems. There is copious work to be done before this can be let out on an unsuspecting consumerate (new word I just invented). I really do not think that GM is ready for real world applications beyond things like getting yeast to produce insulin. Essentially I'm distinguishing between releasing newish organisms into the wild and keeping them in a laboratory or contained industrial setting.

Originally posted by @deepthought
This is one of my major objections to the commercialization of this technology. All new technologies have their problems and CRISPR (which is a lot better than previous versions of genetic tinkering) has its problems. There is copious work to be done before this can be let out on an unsuspecting consumerate (new word I just invented). I really do not ...[text shortened]... newish organisms into the wild and keeping them in a laboratory or contained industrial setting.

The article says the mutations can happen thousands of units away from the actual cut point.
So it sounds like there is some kind of genetic tsunami going on that rattles the cage all the way down the line maybe like a pulse wave that happens BECAUSE the strand is cut, like a vibrating rope cut in the middle, there would be a pulse vibrating down the line and maybe that pulse finds a weak spot that wouldn't ordinarily show up unless jostled by the CRISPR cut itself.