[CLIENT] Client Corrupts When Run While Offline

I have two WiFi networks, one of which is not connected to the internet. Sometimes i forget to switch to the online WiFi before running league, and this causes the client to give me a "Reverted to and earlier version to re-apply a patch, restart the game to proceed" set of dialogues. After I switch to the online WiFi and relaunch the game, it downloads some 30-200 MB of data (so far), which is a problem on metered networks. This problem happens 100% of the time I launch the game on a WiFi with no connectivity.