The <onlyinclude> is within <noinclude> and <nowiki> in the template, but when transcluded the <noinclude> and <nowiki> are ignored and only the part within <onlyinclude> is transcluded. I don't know what should happen when that combination of tags is used. As it's only in the notes and not intended to function as a tag in that template, the < can be changed to &lt; for the onlyinclude tags

T281921 looks similar, so it's likely the bug also prevents creation of the pages. T46199 also looks similar, and was fixed by deleting the page - has that been attempted? If there are no revisions, nothing would be lost.

Could this be because edit summaries are checked for spam, as mentioned in T15599#173812? Removed content can appear in edit summaries in the Wikidata user interface (and other scripts and tools) and there is usually no way to save with a different summary.

It has a page ID (363432) created on 9 June 2014. Between the pages before and after being created there is one missing revision (1637537) so it's probably either that revision or it never had any revision ID

I made enough edits with my alternative account to be autoconfirmed but these rights were not added. There is also a permission error when moving pages with pending changes enabled: "You do not have permission to move this page, for the following reason: You are not allowed to execute the action you have requested."

My most recent edit wasn't automatically accepted. According to Special:ListGroupRights, my rights should include autoreview and movestable but they are missing from https://en.wikipedia.org/w/api.php?action=query&meta=userinfo&uiprop=* - are these rights usually in the list there?

Not resolved, some of the history is still at Help talk:Help talk:Getting started. With the original move, all the watchlist entries would have to be added for the new title, but when moving back most would already be there, so there would be very few, if any, to change - both titles have many watchers so are the lists compared before attempting to write? There's probably no reason to wait for the watchlists to update, as a watchlist cannot block a move; when a template is edited there are can be thousands of pages using that template (and it may cause a similar number of new transclusions of several other templates) but that doesn't block editing.

After purging a property and an item where the property is used, it still seems to be cached somewhere, and if a property is added after the formatter URL is changed, the link created is based on the old formatter URL.

Slashes are still converted to %2F in UK Parliament thesaurus ID (https://www.wikidata.org/wiki/Property:P4527). The formatter is http://explore.data.parliament.uk/?endpoint=terms/$1

Not only mobile site or devices - https://ms.wikipedia.org/wiki/Templat:Interactive_COVID-19_maps/Per_capita_confirmed_cases appears blank in Firefox 83.0. The graph can be seen in preview, and in old revisions, and it was blank in https://ms.wikipedia.org/w/index.php?title=Templat:Interactive_COVID-19_maps/Per_capita_confirmed_cases&oldid=4796396 and https://ms.wikipedia.org/w/index.php?title=Templat:Interactive_COVID-19_maps/Per_capita_confirmed_cases&oldid=4956283 but both display the graph now they are no longer the current revision.

Not sure when this was changed but https://www.wikidata.org/w/index.php?title=Q96884047&diff=1223503993&oldid=1223461969 (3 July) would now be too long. That's the most recently created item with "quotation or excerpt" but there may have been additions to existing items since then or long strings in other properties.

T198108 looks like it was to add an option to change the limit. T154660 was to increase a limit (possibly this one) to 1500 but whatever was changed there doesn't seem to have been reverted. Is there something else that restricts it to 400?

It has started working again. It had stopped a minute before the logs in T253738 so possibly related to that.

The link was in the source of https://en.wikipedia.org/wiki/Template:Aspects_of_music, which is transcluded in the documentation of Template:Rhythm_and_meter.

There was a duplicate (Q89621390) but both were in the query service, merging the items shouldn't remove the data for both.

In this case, and in T185049 and T199210, the error occurs when attempting to view a log entry which the API shows as having "target_title": "Special:Badtitle" (or equivalent) followed by "Talk:" and a title with an interwiki or namespace prefix. (https://en.wikipedia.org/w/api.php?action=query&list=logevents&letitle=Talk:C_Real&lestart=20130307183225)

Probably related; the log entry (https://ml.wikipedia.org/w/api.php?action=query&list=logevents&leuser=Viswaprabha&lestart=20060110235733&lelimit=1) is for a move to a title that translates to "Special:Badtitle/Talk:" followed by another prefix.

The log entry can be viewed using the API (https://en.wikipedia.org/w/api.php?action=query&list=logevents&lestart=20070819174310&letitle=Talk:Allegations%20of%20French%20apartheid/Archive%2001) - the talk page moved to a title that is now invalid and the prefix of "Special:Badtitle/" in the log entry is similar to T190477. The move from the invalid title doesn't have that prefix and can be viewed in Special:Log (https://en.wikipedia.org/w/api.php?action=query&list=logevents&lestart=20070819174422&leuser=Physchim62&lelimit=1 and https://en.wikipedia.org/w/index.php?title=Special:Log/Physchim62&offset=20070819174436&limit=1&type=&user=Physchim62) but it could also be the difference between an invalid title in "title" and one in "params".

API:Mergehistory says that part of a page's history can be merged to another page. Could the revisions be merged to a new page in batches, deleting and restoring one edit each time, or does that also fail?