How do I turn off message waiting indicator light

https://www3.bellmts.ca/mts/support/phone+services/troubleshooting/you+have+no+new+messages+waiting+but+your+phone+says+you+do

Turn off Message Waiting Notification temporarily

1. If you know you have a message waiting, but do not wish to retrieve it immediately, you can turn off Message Waiting Indicators.
2. Press *93 to turn off the flashing light and stuttered dial tone until another message is received in your mailbox.

you have to log in to your account at the phone service provider and reset message waiting indicator. If you have a contract company managing your ip phone service, call them, and say you need the message indicator reset.

you can contact the service provider........

Did the messge waiting light work before?
Does the light flash when there is an incoming call?

try this... FEATURE # 8 0 6
this is a code to shut off the Static Time and Date feature on the set. Usually if this feature is turned on, the set does not flash where there is a message.

Well that is one thing, or the port maybe bad, and a technician maybe required to move that phone to a new port on the phone system.

This feature is country dependent and may not
appear in some countries.
If you have subscribed to the voicemail service
from your local service provider, icon turns
on when you have a new message in your
mailbox. After you have accessed to all the new
messages, icon will turn off automatically. If
you find that the message waiting indication
cannot be turned off by the network, you can
still turn off the message waiting indication with
your phone by the following step :

In idle mode, if voice mail waiting icon is on,
long press the redial key to turn off the voice mail waiting
icon.
Once you choose to delete the message waiting
indication, all the other handsets registered to
the same base station will turn off the message
waiting indication accordingly.

Press down the "find handset" button until the paging beep stops (about 5 seconds) and this will reset the indicator lights on the handsets.

Slide the Nortel Grey Bar above the Hold & Rls buttons to reveal the setup button.

1. Hit that button to show *Options List / # Setup list
2. Press * to go into options.
3. Use the arrow buttons or hit 3 to go into CLEAR MESSAGE WAITING
4. Then hit 3 again to clear the message waiting

This should resolve the blinking light.

To reset the indicator(Red light flashing on handset), press and hold the find handset key for 5 seconds or until the light flashing stops(10 sec).

You can also press #409 on the phone to clear the message waiting indicator.

Resetting the New Message LED
If the LED remains on after you’ve retrieved your messages, you may need to reset
the indicators. With the phone is in standby mode, press and hold find handset on
the base until the paging sound stops (about 5 seconds).