So you probably knew that Scratch was going down for maintenance on July 14th, but apparently, people couldn't save projects at all without downloading them as an SB3 file, including me. Now since July 14th has passed, I'm still not able to save any project, even making very slight modifications to it.

Is anyone else still having this issue? I had to delay multiple updates and projects because of this.

You can fix this issue by logging out of your account in a different Scratch tab, then logging back in.
Also, according to this announcement, the maintenance downtime is cancelled.

Scratch--TheCat wrote:

You can fix this issue by logging out of your account in a different Scratch tab, then logging back in.

I mean tried that and while it does work, I just don't really want to log off and log back in all the time to upload or to update a project. I'll much prefer it if they actually fix it

DaveTheBaby wrote:

(#3)

Scratch--TheCat wrote:

You can fix this issue by logging out of your account in a different Scratch tab, then logging back in.

I mean tried that and while it does work, I just don't really want to log off and log back in all the time to upload or to update a project. I'll much prefer it if they actually fix it

If you did those and your projects won't save, try repeating that a few more times. That's apparently how you would fix that issue.
Also, I believe the Scratch Team is currently trying to fix that issue.