Unfortunately if it's 10 minutes before the start of a mission, we may not be able to help in troubleshooting so please try to test well in advance of a planned Saturday mission.
This is occurring for one of 2 reasons (all fixed in A3Sync):
I'm getting kicked off the server for:
This can either be a game or a mod related issue. Please take notes of what exactly if kicked you for.
If it doesn't specify what you're being kicked for, ensure your plugins are up to date in Arma 3 Sync. If they are, check to see if you're subscribed to that same mod in the Steam Workshop, which has the possibility for compatibility issues regarding different versions and signatures.
When launching Arma ACRE will check what version the client, check what plugin version is in their TS directory and move the plugin as needed.
When Teamspeak is loaded however its enabled plugins are locked as they are. When ACRE tries to update it, it will fail and show an error message with the option to continue.
If this happens you should close both Teamspeak and Arma, launching Arma by itself to move the plugin. It'll give you a message saying it was successfully moved. Hit 'ok', then launch Teamspeak like you normally would.
Sometimes things happen in the process of updating and the plugin ACRE is trying to copy is an old version. The solution is similar to the above but with a couple extra steps:
This is sometimes dependent on how your Teamspeak or Windows sound options are set up.
For Teamspeak, check the playback options in Teamspeak and make sure it's set to stereo and 3d positions for clients.
For Windows, make sure your device is set to stereo audio. This can be changed by clicking the Configure button on the device in the Windows playback devices menu.
This is typically the result of having an out of date version of Java, Arma 3 Sync requires Java 8 and above. You can download the latest version of it here. Multiple installs of Java could still cause it to fail so it's advised to uninstall any previous versions first.