Forced to recreate Cisco System Health Fans on each device reboot

I have a Cisco switch with a System Health Fan sensor on it. Sometimes it appears that the sensor stops working with the following error message:

No such instance (SNMP error # 223)

The only solution I have at the moment is to recreate the sensor fresh, and delete the old one. However this then removes the history on the sensor which isn't ideal.

When looking carefully at the content of 'PRTG Configuration.dat' and comparing the old sensor vs the new sensor, I can see the following OID that is created differently in the new sensor.

Old Sensor:

<name>
  System Health Fans
</name>
<oids>
 1.3.6.1.4.1.9.9.13.1.4.1.3.1035&#x0d;1.3.6.1.4.1.9.9.13.1.4.1.3.1037&#x0d;1.3.6.1.4.1.9.9.13.1.4.1.3.2035&#x0d;1.3.6.1.4.1.9.9.13.1.4.1.3.2036&#x0d;1.3.6.1.4.1.9.9.13.1.4.1.3.3055&#x0d;1.3.6.1.4.1.9.9.13.1.4.1.3.3083&#x0d;1.3.6.1.4.1.9.9.13.1.4.1.3.4047&#x0d;1.3.6.1.4.1.9.9.13.1.4.1.3.4057&#x0d;
</oids>

New Sensor:

<name>
  System Health Fans
</name>
<oids>
  1.3.6.1.4.1.9.9.13.1.4.1.3.1035&#x0d;1.3.6.1.4.1.9.9.13.1.4.1.3.1036&#x0d;1.3.6.1.4.1.9.9.13.1.4.1.3.2035&#x0d;1.3.6.1.4.1.9.9.13.1.4.1.3.2036&#x0d;1.3.6.1.4.1.9.9.13.1.4.1.3.3034&#x0d;1.3.6.1.4.1.9.9.13.1.4.1.3.3064&#x0d;1.3.6.1.4.1.9.9.13.1.4.1.3.4034&#x0d;1.3.6.1.4.1.9.9.13.1.4.1.3.4048&#x0d;
</oids>

The difference is in the oid on the new sensor.

My options appear to be varied, and I would be keen for which one might be the safest option.

1) Find a way of moving the historical data from the old sensor to the new one. Various threads on this, explaining that its not supported (Bad).

2) Edit the 'PRTG Configuration.dat' file directly and save the file. However we are a 24/7 shop, so taking down the server to do this would be a bit of a nightmare. I don't know if there is a way of stopping anything in PRTG from writing to the file while I do the work, and then trigger some kind of reload once I have done the work. Just need to adjust the OID.

history oid sensor snmp