When I booted up Krita today, I've had numerous times where I can't zoom in and out using the scroll on my mouse of being able to move the canvas using the space bar. I can still draw on the canvas and when I close the program and boot it back up it works but that'll stop being the case randomly. Any help would be nice.

Hi,

Can you elaborate on the issues you have ? And specify which OS and Krita version you are using ?
Because it seems like something that started to happen to me too, since a few days.

Here I'm on Windows 10 with the latest Krita release (4.4.3), but it started to happen a few days before, while I still was running the beta version.

At startup, Krita behaves normally, but at some point some keyboard shortcuts and mouse/pen buttons stop working completely : zoom - pan - rotate, brush size (by holding shift), the right-click menu, and even the numpad shortcuts to rotate the canvas. But I can still draw, and other shortcuts still work (like switching to eraser mode, or to switch to another tool), and aside from that the software seems to works correctly.

So far, the only workaround I found is this : double tapping the Tab key makes it work again. But as soon as I click on something that is not the canvas (like on a menu or docker) the issue is back. This is really annoying and I don't think anything changed on my system to explain how it started, so I have no idea what could cause that...

When I start Krita, this issue seems to appear randomly after using it for sometime, but I noticed that if I start the program, then I alt-tab to another software, and then I alt-tab back to Krita, the issue is back.

Anybody else is having these issues ?

I found out on my end what was causing the issue, I don't know if this would help anybody else, but just in case I post it here :

I had to install a big security software suite on my machine (it's kind of mandatory for me during lockdown, for my dayjob when working remote, to access the company server), while before I only used the built-in Windows Defender. And it's the anti-keylogger from this security suite that messes with the keyboard inputs on most graphics software. Photoshop and others were affected also but in minor ways, causing just some glitches, while Krita was rendered almost unusable.
Disabling the feature made it work again.

I have been annoyed a similar issue for half a year while redj's solution doesn't work in my situation. The glich seems occur with all key combo assosiated with mouse/stylus, not limited to zoom and pan but also including colorpicking, line tool, etc. Also relaunch krita/restore settings for krita/inactivate python plugins/ reboot my pc/ reinstall the tablet driver/ reinstall different versions of krita(with appdata folder deleted) don't make any difference.
I have no problem using other painting softwares like CSP or any other softwares on my Win10 PC. However I really enjoy krita's convenient functions and I wonder if there is a direct solution rather than reinstalling the whole OS...