the bonjour function has disappeared from my mac

Reinstall OS X, and never use any Mac "cleaning" product, ever again.

What is not working, that would lead you to suspect you accidentally removed Bonjour?

It's an integral part of the operating system, and cannot be removed through normal means.

You could try Bonjour Browser

<http://www.tildesoft.com>

Or Flame

<http://husk.org/apps/flame/>

It's hard to say, not knowing what printer it is and what "cleaning" product you used. Are you certain you eliminated that product, and that it's no longer affecting your Mac?

In the absence of knowing what it is and just what you did with it, I generally advise erasing the affected Mac and reconfiguring it from the ground up. Some of those products really are that bad. Write back if you would like specific instructions. The first step would be to back up your Mac. To learn how to use Time Machine read Mac Basics: Time Machine backs up your Mac - Apple Support.

Short of that tedious procedure, try this: Delete your existing printer from System Preferences > Printers & Scanners, and add it again. Better yet is to "reset the printing system" as described here: Mac OS X: How to reset the printing system

After you do that you will need to add the printer again according to the instructions here:

OS X Mavericks: Set up a printer

I'm sorry to have to tell you this, but that's what "CleanMyMac" does. Read below.

It is not reasonable to expect a Mac to operate normally after using CleanMyMac. Like many ill-conceived "cleaning" utilities, it is capable of corrupting a Mac to the point that erasing it completely is the only practicable means of recovery. CleanMyMac is not the only example; it is merely popular due to marketing strategies that are as effective as they are intrusive.

There is no practicable way to reverse the effects of having used CleanMyMac2 other than to reinstall all affected files from backups or their original sources. Its developer's uninstallation instructions are ineffective despite their recent claims to the contrary. Only MacPaw, its developer, can know the reason for that, but I can think of two possibilities: either they are purposefully leaving components behind for reasons known only to them, or they simply don't know what they're doing. Neither one of those possibilities is particularly comforting for the user.

Reinstalling OS X alone will have no effect on either removing CleanMyMac or reversing the damage it is capable of inflicting upon a system.

Follow the applicable recovery procedure below:

• If you have a backup that you created prior to using CleanMyMac, now is the time to use it. For Time Machine, boot OS X Recovery, and at the Mac OS X Utilities screen, choose Restore from Time Machine Backup. Choose a date preceding the installation of CleanMyMac.
• If you do not have a backup that predates the use of CleanMyMac, create one now. To do that read Mac Basics: Time Machine backs up your Mac.
  • The recovery procedure will require that you erase the Mac using OS X Recovery, and then create a new user whose contents will be empty. You will then be able to use Setup Assistant to migrate your essential documents including photos, music, work products and other essential files.
  • When doing so, select only your previous User account and do not select "Applications", "Computer and Network Settings" or "Other files and folders". De-select those choices.
  • Subsequent to using Setup Assistant, you will need to reinstall the essential software you may require, once again remembering to install software only from their original sources, and omitting all non-essential software.

To erase and install Mavericks read: OS X Mavericks: Reinstall OS X

To migrate your essential documents read: OS X Mavericks: Transfer your info from a computer or disk and follow the procedure under Transfer info from a Time Machine backup or other disk.

Yes, well nobody tells us that...

Well, I just did. Did you really expect MacPaw to tell you not to use their product?

I provided instructions for Mavericks because your profile indicates you're using Mavericks, and you posted your question in the OS X Mavericks forum. You will need to follow my instructions to recover from the effects of having used CleanMyMac. For Yosemite, the only applicable changes to the above instructions follow the line below.

Good luck.

To erase and install Yosemite read: OS X Yosemite: Erase and reinstall OS X

To migrate your essential documents read: OS X Yosemite: Transfer your info from a computer or storage device and follow the procedure under Transfer info from a Time Machine backup or other storage device.

Nobody tells us that BEFORE we buy those kinds of apps.

There are many who will, but you must perform your own research and draw your own conclusions.

The Internet is overwhelmed by advertisements for all sorts of garbage products you don't need. Software obviously represents just one small category. The vast majority of advertisements are delivered to you courtesy of Google's AdSense program, because performing a Google search divulges the fact you're using a Mac, and (depending on the search terms), may be interested in a software product promising to fix it or to improve its performance. You represent a valuable target for them to exploit, so you are effectively sold as a product to the advertiser. It's a brilliant, wildly successful strategy. The fact you are likely to mess up your Mac by using garbage products does not factor into that strategy at all. It benefits Google, it benefits the garbage software developer, and it benefits their respective stakeholders. You mean nothing — it's your money they want.

If you don't want to be burdened with having to distinguish the malicious from the merely worthless, constrain your Mac app purchases to the Mac App Store.

To learn how to do that read OS X : About Gatekeeper - Apple Support.

You will still find worthless, time-wasting junk in the App Store, but what you obtain there won't harm your Mac, and is easily deleted if you decide you don't want it any more.

Bonjour has some serious issues on Yosemite. It is really frustrating as it is quite random. Restarting your Mac (and the printer) may solve the issue for a while, so you can do your work at least. It is discussed widely. Very often I cannot see other Macs on my network (while I can connect to them using IP address) and I cannot see Bonjour users on Messages (iChat worked perfectly).

I may suggest a series of commands to run on the terminal, if you are comfortable with that (and are the administrator of the computer, you'll have to enter your password):

sudo launchctl unload -w /System/Library/LaunchDaemons/com.apple.discoveryd.plist

sudo launchctl unload -w /System/Library/LaunchDaemons/com.apple.discoveryd_helper.plist

sudo ifconfig en0 down

sudo ifconfig en0 up

sudo launchctl load -w /System/Library/LaunchDaemons/com.apple.discoveryd.plist

sudo launchctl load -w /System/Library/LaunchDaemons/com.apple.discoveryd_helper.plist

en0 represents your network interface

It might be en1 - you can see what you should use by running on the terminal:

networksetup -listallhardwareports

It should be pretty self-explanatory.

Now, this is not a permanent solution. It is much like restarting your computer (which might actually be faster if you are slow with the terminal). But I've been at points where I did not want to interrupt my work and just issued the commands above and I could ("magically") see Shared Computers on my Finder sidebar and Bonjour users on Messages.app.

It might be my router, I don't know - and I shouldn't care. It worked great before - with Yosemite it doesn't.

I also wanted to point out, that there is no way that you can uninstall Bonjour, using a product like CleanMyMac. I've actually used it for years and have never had any issues like that. And actually I think it's a quite good product - I clean up caches, uninstall apps without having leftovers and occasionally manage extensions that may be installed without me knowing. It does not delete system files or messes up with services in any way.

Now, I don't know why John is so much against CleanMyMac. There are others like MacKeeper that use very aggressive advertising and actually are crap apps. Generalizing that any clean-up utility is "ill-conceived" is close to paranoid. Sorry, but I like that 5GB of cache created from internet surfing or logs back when I got a 128GB drive. And I don't like leftovers from apps that I just wanted to try out (OS X does not help at all on that). Having a nice interface for it and not having to dig around my Library folder is more user friendly. And no, I am not affiliated in any way with MacPaw.

I have Yosemite 10.10.5 and have no backup prior to using CleanMy Mac2.

Can I restore Bonjour simply by installing El Capitan?

Thnaks,

Larry