Accu-Chek COMPACT PLUS Owner's Booklet page 79

The test drum 90-day use-by
period has expired. If the correct
time and date were set on the
meter and the drum door has
not been opened since the
installation of the test drum,
discard the old test drum and
insert a new test drum.
Chapter 5: Maintenance and Troubleshooting 77
ACCU-CHEK Customer Care Service Center 1-800-858-8072
The drum door was opened
and closed with a partly used
test drum inside or a partly
used test drum was inserted.
If there was a partly used
test drum in the meter and it
took longer than two minutes
to replace the batteries, the
year, date, and time have
to be reset. When the year,
date, and time are reset, the
meter does not know how
long the partly used test
drum has been in the meter.
You should run a control test
to verify that the test drum
is useable. See Chapter 2,
"Why Run Control Tests?"