This fix was written by Dr. Duke from the HLLTC and reposted here by GOD-sSs-END. This fix will repair comms for most players in Hell Let Loose and other games.
You're in the middle of a firefight or a tank duel. Or perhaps you're coordinating an offensive or just enjoying a nature walk through the beautiful battlefields of Hell Let Loose. Suddenly, you're no longer communicating in-game. Your comms are out! It can happen anywhere, to anyone, and it happens without mercy. There is a fix.
Try These Steps First
1) Change servers
2) Update your audio drivers
3) Check your mic cable
4) Restart the game and hope for updates
5) Restart your PC and hope for updates
Editor note: You can try closing the game and performing a "hard" close on Steam. Press "Ctrl + Alt + Del" to bring up the task manager. Click on "Steam" and then click "End Process." Once the process has ended, close the task manager and restart steam and then restart Hell Let Loose and test your comms.
If these don't work, that means the problem is likely a VOIP system failure. The meat of this article is dedicated to fixing the loss of VOIP with the best fix I've found. To fix the loss of comms in Hell Let Loose, you will need to delete certain corrupted logs files from your local game files. It's easy, and you'll be back in the game and communicating in no time.
What is VOIP?
VOIP stands for "Voice over Internet Protocol." VOIP allows voice communication for games and programs over the internet. This system is normally taken for granted as it is standard in almost every Web-based program. When it is gone, you realize what kind of mess you're in. Simply put, without VOIP, you are mute and deaf to teammates. Of course, there is always text chat. But the enemy won't stop suppressing you, and there's just no time to write a love letter to your team.
This solution came to me after hours of searching forums, countless game and computer restarts, and a complete reinstall of Hell Let Loose. I was out of options and desperate, so I did the thing that no one should ever do: I randomly delete local game files.
It was a great risk to take, but by the grace of the HLL gods, I managed to not only fix the problem but fix it every time. And so, I impart this knowledge to you, so that you may not have to endure the pain that I and others have.
Please Read All of the Steps Before Performing Them
1) Close all instances of the game
2) Go to your Steam library
3) Navigate to Hell Let Loose
4) Right-click on Hell Let Loose and scroll down to "Manage"
5) Click on "Browse Local Files"
This will have bring up the local files explorer on you computer.
6) Find and open the "Logs" folder
7) In the "Logs" folder, select all "UploaderLogs" and delete them
The amount of logs will differ from user to user (see below). It is IMPORTANT that you DO NOT DELETE the logs folder itself. Just the logs inside the folder.
8) After deleting all logs, close the file tabs and start up the game. Join an empty server as a squad leader and check all comms channels (command, squad, and local) to make sure they work. If so, you're done! Go give 'em hell. If you still don't have comms, don't be discouraged. There is still the "nuclear option."
The Nuclear Option
If you didn't already know, VOIP systems for Hell Let Loose are provided by the fine fellows over at Vivox. After talking with some players who have tried Vivox tech support, they were told that a firewall in their router or data interruption by their ISP ("Internet Service Provider") caused them to lose VOIP authentication. This authentication is vital for in-game comms to work. This was likely an accident caused by a software update or other service maintenance. After talking with tech support, they were able to get their issues resolved. Below is the help page for Vivox; give them a shout as well as asking your ISP if there was any maintenance or software changes that could have caused the issue.
I hope this is a help to those who need it. If so, spread the word. If not, hang in there. The developers of Hell Let Loose are hard at work sorting issues like this. A permanent fix for loss of VOIP is on the way. You can count on it.