Could this be related to Wikidata-Ugly-Cat-Trailblaze (wb_terms trail blazing)

hmm, looking at the screenshot I'd tend to say "probably not", as the new formatter code is only use to format items Q1..Q100,000 in statements, and all Q-IDs in the picture are way beyond that range.
This does not mean that I close the possibility that work was somehow resulting in this problem, although that would be some unexpected side effect if it was related.

I regularly use the WEF Framework gadget, and over the last several days I am seeing this problem come and go.

There is a variation in the problems the range I am seeing is

• no labels render at all through the gadget; (least often)
• the labels in the form render, though labels in the dropdowns do not, the selections do not
• the labels in the form and the dropdowns render , though the typeahead choices do not render (when playing up this is the most regular misbehaviour)
• behaving normally

The problem can last for half a day or so with the variations, though again one misbehaviour predominates.

Does this occur for multiple people on single items?

Could you write some steps to try to reproduce? Or example links if it is happening right now?

To reproduce, I just click "random item" a few times, one will show up very quickly.

Example right now: The "published in" statement on https://www.wikidata.org/wiki/Q40220984 . The statement target (Q27713832) has an en label.

In T205556#4651725, @Magnus wrote:

To reproduce, I just click "random item" a few times, one will show up very quickly.

Example right now: The "published in" statement on https://www.wikidata.org/wiki/Q40220984 . The statement target (Q27713832) has an en label.

Thanks!
Managed to reproduce and also found https://www.wikidata.org/wiki/Q30800580

Could also be related to T204791
It is probably something bad ending up in the parser cache for some reason.

Here are a collection of example items that have the issue and the associated parse times.

https://www.wikidata.org/wiki/Q16985906 20180924223337
https://www.wikidata.org/wiki/Q53450252 20180925194242
https://www.wikidata.org/wiki/Q4807677 20180927074158
https://www.wikidata.org/wiki/Q51417582 20180925043035
https://www.wikidata.org/wiki/Q24780602 20180926015955
https://www.wikidata.org/wiki/Q24015331 20180926073525
https://www.wikidata.org/wiki/Q23232005 20180925163742
https://www.wikidata.org/wiki/Q45150234 20180926104514
https://www.wikidata.org/wiki/Q34658381 20180927115124
https://www.wikidata.org/wiki/Q21165037 20180926232452
https://www.wikidata.org/wiki/Q28775820 20180925011256
https://www.wikidata.org/wiki/Q38142153 20180925081939
https://www.wikidata.org/wiki/Q49308747 20180927180532
https://www.wikidata.org/wiki/Q6247542 20180926161726
https://www.wikidata.org/wiki/Q11360786 20180927030305
https://www.wikidata.org/wiki/Q43566379 20180927001424
https://www.wikidata.org/wiki/Q43063590 20180927140916
https://www.wikidata.org/wiki/Q36138238 20180925165035
https://www.wikidata.org/wiki/Q37017470 20180927015100
https://www.wikidata.org/wiki/Q23388388 20180925083255

@Addshore As I mentioned above, whilst I a having some issues with WD directly, I am having greater issues with WEF framework tool's lookups. As I create items and do the lookup for matching terms it is finding items successfully, though the rendering of the name into the visible for selection is regularly not occurring. If it was anything but the lookup I could say I had caching issues, however, the lookup will be fresh name every time.

So the main thing that we are seeing here (badly cached pages in the parser cache) seems like it could have been some temporary issue (although I have no idea what the issue was).
All of the pages I linked to in T205556#4654519 are now fine after re parses, and hitting Special:Random repeatedly, I can no longer find any pages with issues :/

If anyone does spot another page where this is happening please write a comment on this ticket including the following:

1. Link to the page
2. Parser cache key & date of the page.

The parser cache key nd date of the page can be found in the HTML source of the page and will look like this (you can just search for pcache):

<!-- Saved in parser cache with key wikidatawiki:pcache:idhash:44779291-0!wb=3 and timestamp 20181011141845 and revision id 598318328
 -->