First of all: I installed the mod, started the game and used the second tier beacons without any problems at all! Great mod!
But a friend of mine had an issue. He tried to join the game, Factorio synchronized the mods and restarted. After the restart he faced the following error:
"The given sprite rectangle (left_top=0x0, right_bottom_34x24) is outside the actual sprite size (left_top=0x0, right_bottom=84x22).
See the log file for more information: Beacon2/graphics/entity/beacon/beacon-module-lights-3.png"
Both beacon-module-lights-3.png and the beacon-module-lights-1.png have only a width of 22px, but beacon-module-lights-2.png and beacon-module-lights-4.png have a width of 24px. We just replaced the both smaller files with the larger ones and the game started just fine (we accepted the possible visual error that could occcur).
My setup: Win 10, Steam
His: Win 7, Steam