Why did scrolling stop working on my Mac after installing a mouse app?

Most likely two pieces of software are modifying the same scroll events. macOS lets more than one utility tap the event stream, and each one sees the output of the one before it. If one inverts a scroll and another inverts it back, the result is a scroll that appears to ignore your settings. Vendor mouse drivers, smooth-scrolling utilities and key remappers can all do this, as can a scrolling utility left installed and forgotten.

How do I tell whether a third-party app is breaking scrolling on my Mac?

Start the Mac in Safe Mode, which stops third-party login items and drivers from loading, and test scrolling there. If scrolling behaves correctly in Safe Mode but not in a normal boot, a third-party app is responsible. Restart normally and quit scrolling utilities one at a time until the behaviour changes.

Why did scrolling break after a macOS update?

A utility that taps scroll events depends on macOS internals that can change between releases, and Accessibility permission is often reset or invalidated by a major update. After an update, re-grant Accessibility permission in System Settings under Privacy and Security, and check whether each scrolling utility still supports that version of macOS.

Can two mouse utilities run at the same time on a Mac?

They can both run, but if both modify scroll events the results are unpredictable, because each one acts on what the previous one produced. The reliable approach is to let exactly one utility own scrolling and configure everything else to leave scroll events alone.

Mac scrolling stopped working after installing an app

Updated September 2026

Short version: two things are probably rewriting the same scroll events. macOS allows more than one utility to modify scrolling, and each one acts on what the previous one produced — so one can quietly undo another, and the symptom is settings that appear to do nothing at all.

What this looks like

The tell is that scrolling is not broken so much as unresponsive to settings. Typical reports:

You change scroll direction and nothing happens, in either direction.
Scrolling was fine, then a macOS update or a new app landed and it was not.
One app scrolls correctly and another does the opposite.
Direction is right but speed is wildly wrong, or the other way round.

If the wheel does nothing at all — no movement in any app, including after a restart — that is more likely hardware or pairing than a software conflict, and this guide will not help.

Why does this happen at all?

A scrolling utility works by tapping into the stream of input events macOS generates and altering the scroll ones as they pass. Nothing stops a second utility from tapping the same stream. When that happens they form a chain, and the second one sees the first one's output rather than what your mouse actually sent.

Two inversions cancel. Two speed multipliers compound. Neither app is malfunctioning; they are each doing their job to the wrong input.

How do you confirm it in a few minutes?

Step	What it tells you
Boot into Safe Mode and test scrolling	Safe Mode blocks third-party login items and drivers. Correct scrolling here means the cause is third-party software, not macOS or hardware.
Restart normally, quit scrolling utilities one at a time	Behaviour changing as you quit one identifies the culprit.
Check System Settings → General → Login Items & Extensions	Finds utilities you installed and forgot, which is the usual answer.
Check your mouse vendor's driver software	Vendor drivers often smooth or remap scrolling by default, and count as a second modifier.
Re-grant Accessibility permission	Major macOS updates frequently reset it. Without it a utility runs but silently does nothing.

Apple documents the Safe Mode procedure itself — see Apple Support: start up your Mac in Safe Mode.

Which kinds of app cause it?

Not a list of products, because the category matters more than the name:

Mouse vendor drivers. Several smooth their scroll output before macOS sees it, which changes the shape of the events other utilities inspect. Logitech's Options+ is one that behaves this way.
Smooth-scrolling utilities. Their entire purpose is rewriting scroll events, so they conflict with anything else doing the same.
Key remappers and automation tools. Many can rebind scroll events even when that is not what you installed them for.
A second scrolling utility you forgot about. Common after trying a few before settling on one.

How do you fix it?

Let exactly one piece of software own scrolling. Decide which utility you actually want, then turn scroll modification off everywhere else — including in your mouse vendor's driver, which usually has a setting for it. Quitting is not always enough; some install a login item that restarts them.

After a macOS update, check Accessibility permission before assuming anything is broken: System Settings → Privacy & Security → Accessibility. A utility with the permission revoked keeps running and silently stops working.

Mouse Scroll: Reverse Wheel

Watches for this specific problem: if another utility is also modifying your scroll events, Mouse Scroll tells you, instead of leaving you to work out why the settings feel wrong. It sets scroll direction, speed and a sideways modifier for mice without touching how your trackpad behaves. macOS 14 or later, a one-time purchase, sandboxed with no network access at all.

Download on the Mac App Store →

More: Mouse Scroll overview · All guides