Sometimes one or more projectors will incorrectly swap the left & right eyes (the wrong image is being displayed for the wrong eye). It makes it difficult to look at the screen, especially if you are looking at the edge of two screens.
When the test pattern is shown. The center left & center right are combined. If that is incorrect, then looking through one eye will show red and looking through the other will not show red (in addition to left & right being wrong). When troubleshooting, hide one of those projectors and it is much easier to see which projector has the 3D incorrectly swapped.
If the lines on the test pattern do not line up, then it is likely the CAVE Config files.
If closing an eye does not make either the “left” or “right” bars disappear, then 3D stereo is not working on that projector. On the Render Node (make sure you're not accidentally looking at the head node), open the Nvidia driver. On the list of menus on the left side, click the synchronization one. When that page is open, all the checkboxes should be checked on the list of monitors. If they are not checked, then click a monitor icon on the list above (any of them), and then see if checkboxes check themselves, or maybe you have to check them. Then click save or apply.
On the small rack behind the center screen, you'll see a series of splitters with BNC connections. Find the connection that corresponds with the problem projector (see list below), remove, wait 2 seconds, then reinsert the connector. The projectors can stay on the whole time. Take another look at the test pattern and see if the eyes are still swapped. Keep repeating until the eyes are no longer swapped.
The order below match the order on the crestron.
Another thing to try is to go into the Nvidia synchronization settings. Click on another monitor other than mosaic. DO NOT CLICK apply. Then click on mosaic again. Then click apply. Sometimes that can have an affect according to Jason Keeney