Client crash welding/building block by hand on grid with active projector
I've had this happen so many times I've been able to narrow down the scenario that causes it, a bit, and find a workaround.
1. You have a grid with an active projector on it, or on a grid linked by connector, and
2. you place a block on that grid, OR hand-weld a projected block (welding by ship does not trigger the crash)
Sometimes the client will crash (not to desktop, but you get kicked from the game, after a 2-5 second "game paused"/"connection problem".) When this happens, the auto-rejoin fails, and actually seems to sometimes cause the server to crash.
Re-joining manually after a short (10 second) wait works. Once this starts happening, it will happen indefinitely, every time you do step 2, until you perform the workaround:
1. Turn off all projectors on the grid, and on grids attached by connector. (If you miss a single one, the workaround fails.)
2. Build a block on the grid (doesn't have to be fully welded, just placed) and grind it.
The problem should now be "fixed", and you can turn any required projectors back on. It'll probably happen again eventually though.
My only experience with SE in the last few months, when I've been noticing this, has been on a modded server, however none of the mods have anything to do with projectors. Maybe others have experienced this on non-modded servers.
When I'm back on the game and this happens again, I'll attach the log.