Alan i am having the same issue. I have webroot. pd service for malwareand rootkit problems but no antivirus. So I added the avg free antivirus which has worked well for 2 weeks . All of a sudden today after updating now it won't load and says contact customer service . Which as soon as they heard it was free they said come here. 
any ideas? i don't want to kick webroot of for free antivrus … plus now the webroot won't work either
Hello Robert,
I regret for the inconvenience caused. Please be informed that it is always recommended not to use multiple security software in a computer. It seems that a recent update from both this security programs might have conflicted and that is why AVG went into passive mode. To fix this issue, I suggest you to remove all the other security software from your computer.
Every since the last AVG update AVG has been automatically going to Passive Mode. Computer, Web&Email, Hacker Attacks, Privacy and Payments all listed as Not Protected. If Fix Now is selected display indicates another antivirus is running on the PC and to either run uninstall on the named antivirus or stay in Passive Mode. for the past couple of years AVG played well with Malwarebytes and SuperAntispyware. Why an issue now? Would have been nice to know before i renewed AVG.
User Dave ziegler has posted their own topic (https://support.avg.com/answers?id=906b0000000E0m3AAC).
AVG Guru
Hello Robert,
I regret for the inconvenience caused. Please be informed that it is always recommended not to use multiple security software in a computer. It seems that a recent update from both this security programs might have conflicted and that is why AVG went into passive mode. To fix this issue, I suggest you to remove all the other security software from your computer.
Bob,
I'm glad to know that your issue has been resolved.
I appreciate all your efforts in trying to fix the issue.
Please feel free to contact us for any further assistance with AVG.
Thank goodness this update came out about a week before I need to update AVG Protection on all of our family's computers. I've already purchased the new 2017 Protection unlimited devices 2yrs but today that will be going for sale on eBay. It seems unbelievable that AVG is standing by its upgrade which disallows its own operation if its customer has another program such as Malwarebytes running.
I did manage a workaround. Turned off real time protection on both Malwarebytes and superantivirus. Rebooted AVG was ok. Turned RTP back on for Superanti and rebooted. AVG was ok. Adjusted the settings for RTP in MB, turned off RTP for web Protection and Ransomwear as AVG already does that, and AVG is running ok. Thanks for all the help everyone!
Bob, Do both your Malwarebytes and SuperAntispyware progs have real-time protection?. If so, that could be your issue as well (http://avgclick.me/ConflictingApps) [Scroll Down… Malwarebytes' Anti-Malware].
AVG Guru