IHC-200 shows Fr code at startup

I have had this controller for many years and it has worked well.

I moved 2 years ago and boxed it up. When I try to use it, I get Fr in the display.

If I unplug it, hold the Set button till I plug it in (then release the Set button) and before it displays the Fr code I press the increase button I get the following:

a) Fr is displayed in PV
b) 210 is displayed in SV
c) work 1 light comes on

After 5 seconds the Fr is displayed.

If I press the decrease button (instead of the increase), I get the following:
a) 21.2 C is displayed in PV
b) 210 is displayed in SV
c) work 2 light comes on

Again after 5 seconds the Fr is displayed.

What does the Fr code mean?
Thanks!

Hello,
Maybe it says ER?
If it can’t be cleared, the probe may be faulty.

Yes it is an Er - the lower leg of the E is not lit. I can’t clear it. Thanks for your reply.