My friends and I play with a number of mods, but we've noticed that if we take any of the civics from this pack, that player can no longer re-select that species if the game is saved and relaunched (or if the player disconnects and needs to reconnect). The species does not appear on the multiplayer species select screen when joining a multi-player game. This seems to include civics that are applied from events / ascendencies.

There is a single player work around. Launch the game, use the console to swap to the problem race, use console commands to remove the trait. Swap back to appropriate species, save the game. Then re-load the multiplayer lobby. This edit does trigger the government reformation 20 year cooldown, and takes a few mins to fix, but it does seem to be a work around for now.