I found this information while searching for "Point 1 invalid" message.
NMEA 2000 signals can be hampered by resistance, which increases with cable length, so keep the length for a single drop cable to less than 20 feet. If you require a longer cable run, use a T-junction in the middle of the run to tie in 12-volt DC power. Augmenting the power helps prevent an excessive drop in voltage.
It's worked correctly ever since I added the additional power input.