Has anyone heard of "Microsoft Nework Security"

Your tech sounds like he's trying to screw you.  So what if Microsoft didn't build it - Microsoft didn't build Acronis, or Adobe, or iTunes, or blah, blah, blah.  Avira is a Windows app and is supported on Windows just fine.  

What errors are showing up excactly.  You could have issues with your OS, or they may be warnings you can ignore - messages in logs don't always mean there's something catastrophic.  Is your version of Avira causing you issues?  If not, it's fine as long as it is running and able to update with the latest definitions.

There's nothing wrong with using Malwarebytes free.  The free version just does not do realtime scanning - you must run scans manually after the trial period so there is no realtime protection.  In some instances, you may not want to have multiple security programs running at the same time though - they may detect each other as a conflicting app and try to cancel each other out (block what the other is trying to do to protect you because it thinks the other one is trying to do somethign bad). 

Use the free version of malwarebytes in conjunction with Windows free version of Windows Defender, which is part of 8.1 and 10 and can be downloaded as an add-on for free for Windows 7 as part of Windows Security Essentials - direct link from Microsoft:  https://support.microsoft.com/en-us/help/14210/security-essentials-download and that should be good for most people - this is my base setup at home and it's cheap and good.

I would not pay $250 for Avira or any security software.  For $60 you can get a 2 year subscription of malwarebytes with full protection - a far cry from $250 for Avira and it would probably serve you better.  I run malwarebytes and Windows defender in conjunction with each other and it has served me well.  I'm lucky enough to have the original lifetime malwarebytes license before it became subscription based, but it's one of the softwares I would not mind paying for.

If you have Comcast, you can get McAfee for free from them - your ISP (if not Comcast), may offer somethign for free as well. Honestly though, Windows Defender with malwarey bytes (especially if you spring for the full vesion), is plenty good. 

Thanks Bobbo, I'll look into it.

CotS

Be warned I am currently having troubles with Antimalwarebytes Antimalware on Windows 10 Creators update.

It did not happen in the original 15063 build but with a later CU Windows decided to disable Defender in sake to promote Anti-Malware to the primary 3rd party AV solution and there is nothing i can do. The Defender functionality is currently broken and disabled and there is nothing I can do.

I am in touch with the Malwarebytes support.

Karl, I have the same issue with MalwareBytes and an open case.  They sent me a newer version of the MBAM cleanup tool (mb-clean-2.4.1.1007 - http://downloads.malwarebytes.org/file/mb_clean) it wasn't available on their website yet and not sure if it has been updated or not since then, but attached if you want to compare and give it a try.  They had me completley remove everything, reboot... Windows Defender took over and updated andthen I reinstalled the latest MBAM from scratch again.  

That did the trick... well for a few days, then MBAM was listed as my AV again, but somehow, Windows Defender is showing up as my AV now and not MalwareBytes so I'm still keeping an eye on it.  I submitted some additional logs from mb-check-3.0.5.1004.exe and FRST64.exe as requested a few days ago, but haven't heard anything back from them. 

Funny, a guy named Günter requested the same to be done from me.

I have notified him about your case and that this happens on all of my Malwarebytes 15063.138 Windows installations, so I hope they don't come around with an excuse :)

Imho I think that Microsoft destroyed it by taking Malwarebytes into the list of AV vendors, but this all does not explain why Defender cannot be started anymore. The mb clean tool at least restored the corrupted views in the security center (with some new upcoming UI glitches).

I am curious how they are going to fix this. Here is my Feedback App post for this: https://aka.ms/Aulws8

btw, I was offered to use mb-clean-2.4.1.1015.exe. Seems they are working fast on this tool :)

At least they're actively workingn on it and trying to get it ironed out - hope they get it sorted soon though.

For the past 3-4 days, Malwarebytes and Windows Defender have been playing nice for me.  I'm tempted to finally update NG 6116 to the current version now.

so you say that both are active and working? Then you are ahead of me. :/

At least for now, it seems to be working again - it reverted back one time after running the cleanup, but magically fixed itself again.  It's been "good" for a couple of days now.