try freshing that page & clearing the cache (CTRL+F5) and verify that your system actually has the lastest update.
Done and done. Still no result. Other templates works fine and gives the expected output.
take screenshot of
{{ states.sensor.unifi_gateway_firmware_upgradable.attributes }}
in template editor.
and
{{ states.sensor.unifi_gateway_firmware_upgradable.attributes['USG-PRO-4'] }}
{{ state_attr('sensor.unifi_gateway_firmware_upgradable', 'USG-PRO-4') }}
The only explanation is that USG-PRO-4 has hidden characters in it. What integration is creating this entity?
This one.
Write an issue against it. The attribute should be usable. For the time being try this:
{% set key, value = states.sensor.unifi_gateway_firmware_upgradable.attributes.items() | list | first %}
{{ state_attr('sensor.unifi_gateway_firmware_upgradable', key) }}
Thank you, I will do that.
Is it possible that one of the letters in USG-PRO-4 is not simple ASCII? I encountered a problem where the value the user had posted contained a C except it wasn’t ASCII Code 67 but a Cyrillic character with different encoding.
In this thread, the OP has been posting screenshots, whereas we have been posting text. If the OP copies our text (all ASCII) to perform the tests, then it won’t match the attribute’s value if it contains a non-ASCII coded character.
Yeah, it’s a long-shot because that string certainly doesn’t look like it contains some special Norwegian character but it might be worth eliminating this edge-case. If the OP copy-pastes the text from the Template Editor’s results pane to a post, we could inspect it (assuming no conversion takes place during copy-paste).
It’s either that or hidden characters like 0x00. Either way, you and I won’t be able to see it.
Maybe not a null (not transferred in copy-paste) but it’s possible to detect non-ASCII characters by examining their hex values. That’s how I spotted the Cyrillic c in this thread.
I would, but there’s nothing to copy…
In your post you displayed a screenshot of the Template Editor whose results included a listing of all attributes.
Ah!
{
"USG‑PRO‑4": true,
"friendly_name": "UniFi Gateway Firmware Upgradable",
"icon": "mdi:database-plus"
}
yep… odd characters for sure. Here’s the ascii rep "USG‑PRO‑4"
with that being said, this should work (You have to copy this, do not type it out):
{{ state_attr('sensor.unifi_gateway_firmware_upgradable', "USG‑PRO‑4") }}
That worked, thanks!
How did you convert it to a working format? Pretty soon that sensor will populate with other attributes as FW releases on my other devices so I’d like to possibly do it myself to not take up your time 
I didn’t convert it. I just copied what you pasted ;). I changed the encoding to ascii to see what it looks like without utf-8 encoding.