macOS 11 Big Sur Problems: How to Fix the Most Common Issues

Since macOS Big Sur was released to the public, we’ve heard about several bugs and errors that come with it. While some issues might require Apple’ official fixes , you can deal with pretty much all of these yourself. So, here is how to fix the most common macOS 11 Big Sur problems.

How to Fix macOS Big Sur Download & Install Problems

macOS 11 Big Sur problems

Many people ran into download problems when trying to install macOS Big Sur right on its launch day. Even though Apple’s server seems to be okay, downloading the new macOS update is quite difficult for some users. In fact, “lost connections” and “slow download speeds” are the most common problems when it comes to macOS update.

So, if you encounter these download issues, try using an ethernet cable instead of Wi-Fi. This will stabilize and speed up your download process significantly. On the other hand, if you can’t plug in or it doesn’t work, we suggest you restart your router and your Mac. Here is a more detailed guide to fix macOS Big Sur download and install issues.

How to Fix macOS Reinstallation Errors on M1 Macs

Shortly after the launch of the new M1 Macs, users have reported a few macOS reinstallation errors on M1 models. As a result, these machines are non-functional after the macOS update.

Luckily, Apple just posted a support document for users who are experiencing this issue. It seems like the problem only occurs if you erase or restore your M1 Mac right away before upgrading to macOS Big Sur 11.0.1. 

In the document, Apple suggests creating a bootable installer using another Mac. Otherwise, there is a step-by-step Terminal guide to help you restore your Mac to a functional state. Either way, you should be able to use macOS Recovery normally when reinstalling the new macOS update afterward.

How to Fix macOS Big Sur Bluetooth Issues

Unfortunately, the Bluetooth connections might get affected after installing macOS Big Sur. Luckily, there are some troubleshooting for you. Let’s start with turning your Bluetooth off and on again. And, if that doesn’t work, try this:

  1. On your Mac, click on the Bluetooth icon in the upper right of the screen.
  2. Open “Bluetooth preferences“.
  3. Disconnect all devices that are now paired with your Mac.
  4. Then, start the pairing process again.

However, in case none of that works, our plan B is delete the Bluetooth.plist file. No worry, it’s totally safe. Follow these steps do it:

  1. Go into Finder.
  2. Click on Macintosh HD.
  3. Then, open the Library.
  4. Scroll down and open Preferences folder.
  5. Here, you will see 2 files called “” and ““.
  6. Delete both files.
  7. Reboot your Mac and try your mouse again.

Wi-Fi Dropping, Slow, Other Wireless Problems

Troubleshooting macOS Big Sur Problems & Issues

If you’re having trouble connecting to a Wi-Fi network or unable to access the internet properly after updating to macOS Big Sur, you’re not alone. Many users have reported that frequently connection drops, Mac doesn’t reliably connect to Wi-Fi or slow network performance.

Although software problems could be the reason why you’re having this, other things like DNS settings, interference from USB devices, and wireless router/modem issues might also prevent you from connecting to your Wi-Fi. So, try resetting your Wi-Fi router to see if it fixes the problem.

If it didn’t, the other options are making a new network location with custom settings or Wi-Fi configuration in macOS Big Sur. Also, resetting the SMC and NVRAM can sometimes help in resolving Wi-Fi issues too.

How to Fix macOS Big Sur App Problems

App developers are still rolling out updates to its apps in an attempt to stabilize the overall performance. So, make sure all of your apps are up-to-date. If your Mac apps still don’t work, the best way is restart your Mac, then delete all problematic apps, and download them again.

How to Fix macOS Big Sur Performance Issues

macOS 11 Big Sur problems

If you feel like your Mac is slower than usual right after installing macOS Big Sur, you aren’t alone! In this case, you should wait for a couple of days or restart your Mac to see if the software performance improves first. Then, if your Mac is still slow, you might need to do a Clean install. This can have a tremendous impact on your Mac’s performance.

How to Fix macOS Big Sur Touch ID Problems

Apparently, even the Touch ID isn’t an exception here. Before you do anything, you need to update your fingerprint now. Here is what you should do. Open the “System Preferences” and go through the fingerprint setup process again. However, if re-adding fingerprint doesn’t work, the next option is to reset your Mac’s SMC.

How to Fix macOS Big Sur Mouse Issues

If you’re facing this bug, be positive because this isn’t a hardware issue. And, you only need to delete some files in order to fix it. Here is how to fix macOS Big Sur mouse issues:

  1. Go to Finder.
  2. Click on Macintosh HD.
  3. Open Library.
  4. Scroll down and choose the Preferences folder.
  5. Find a file called “
  6. Then, delete this file.
  7. Finally, reboot your Mac and try reconnecting again.

Battery Drain after macOS Big Sur Update

Shortly after installing macOS Big Sur, you may notice that the battery on your Mac is draining faster than usual. This is mostly due to some background tasks and indexing after the update. Usually, this is temporary since the battery performance will go back to normal after a few hours once all the background activity and optimizations are complete.

However, if the battery drain persists, you may have to check the “Activity Monitor” to see what apps have the biggest impact on your Mac’s battery performance. 

On your Mac, open Activity Monitor by using the Command Space keyboard shortcut. Then, click on the “Energy Impact” to sort apps based on their battery impact.

Noisy Fans after Installing macOS Big Sur

Don’t worry if the fan on your Mac sounds louder after installing macOS Big Sur. Although the update is complete, macOS will continue to optimize for your device by performing background tasks and indexing for a couple of days. This operation utilizes more system resources. Therefore, the fan on your Mac will kick in and work at a higher RPM to cool down the system component. When it is complete, the fan behavior should go back to normal.

Apple News Initiates Large Background Downloads

Some users recently reported that they are running into a big issue with the Apple News app. Specifically, the app is causing extremely large background downloads. These downloads will slow down the performance on a Mac drastically as they take up a large number of resources. If you want to see whether the issue is affecting your Mac or not, open Apple News and check it out in Activity Monitor.

It’s unclear if Apple will fix this issue in the next update. But fortunately, there is a quick manual fix for it. Here is what you need to do:

  • Open System Preferences on your Mac.
  • Click on Apple ID in the top right corner.
  • From there, select iCloud on the left side of the screen.
  • Once there, you’ll want to scroll down and uncheck News to turn off iCloud syncing.
  • You can then choose to keep iCloud News data on your Mac or delete it. If you choose to delete it, the data will stay put on your other Apple devices.

Fast User Switching Bug

According to reports from the MacRumors forum, several M1 Mac users running Big Sur are facing an extremely annoying bug with the Fast User Switching feature. The feature reportedly prevents users from closing their screensaver. This bug leaves the Mac unusable until its lid is closed and open again, the Alt+Comand+Q key combination is used, or the Power/Touch ID key is pressed.

The Fast User Switching bug has been reported on ‌M1‌ ‌MacBook Air‌, ‌M1‌ 13-inch MacBook Pro, and ‌M1‌ ‌Mac mini‌ models. It also occurs on all versions of ‌macOS Big Sur.

Currently, there is no specific fix for it, but you can disable Fast User Switching to avoid this bug. To do so:

  • Launch System Preferences
  • Select Dock & Menu Bar panel
  • In the side column, scroll down to Other Modules and choose Fast User Switching.
  • Uncheck the box next to Show in Menu Bar or Show in Control Center (you may need to uncheck both).

After all, if none of the above methods works, it’s a good idea to downgrade to a more stable macOS version and wait for Apple’s performance patches.

What issues you’re experiencing after installing macOS Big Sur? Let us know in the comments!

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