I saw that this issue is still occuring to me in mobile as in desktop, @Aklapper, @Pginer-WMF. This is really a bug.

@ngkountas, it seems there is an issue in the algorithm to find the place to insert new section. Can you please check?

@Pginer-WMF, @ngkountas: I saw that this error is also occuring on Bengali Wikipedia, at translating from english to Bengali

@RodneyAraujo could you provide some more information(source language, article title, section title) to reproduce this issue on Bengali Wikipedia, please?

In T281739#7080907, @ngkountas wrote:

@RodneyAraujo could you provide some more information(source language, article title, section title) to reproduce this issue on Bengali Wikipedia, please?

I've tried with this: https://bn.m.wikipedia.org/wiki/%E0%A6%AC%E0%A6%BF%E0%A6%B6%E0%A7%87%E0%A6%B7:%E0%A6%AC%E0%A6%BF%E0%A6%B7%E0%A6%AF%E0%A6%BC%E0%A6%AC%E0%A6%B8%E0%A7%8D%E0%A6%A4%E0%A7%81_%E0%A6%85%E0%A6%A8%E0%A7%81%E0%A6%AC%E0%A6%BE%E0%A6%A6?page=AMiBA&from=en&to=bn&sx=true#/sx.

@Jpita could you validate that this issue exists in production wiki? I followed above link but was unable to replicate it.

I've found a different issue while investigating this one (will create a new ticket but will post here for investigation cause it might be related):

• https://sx.wmflabs.org/index.php/Special:ContentTranslation?page=Gnaeus+Calpurnius+Piso+%28consul+23+BC%29&from=en&to=es&sx=true#/sx/sentence-selector
• after selecting the "Background" section to translate, the skip button is not available when it should
• I cannot select a different sentence to translate using the mouse/tap

• once I click "apply" in the title, then the bottom buttons are blocked and the "loading gif" never finishes spinning

• the last call made was a "preflight" call, never saw this before
• if I select an article with more content to translate, this issue doesn't happen, it seems to be related to the number of sentences/paragraphs

In T281739#7107562, @Jpita wrote:

• the last call made was a "preflight" call, never saw this before
• if I select an article with more content to translate, this issue doesn't happen, it seems to be related to the number of sentences/paragraphs

Thanks for surfacing this @Jpita.
A first impression guess based on the comments above is that this could be connected to the process of pre-fetching the translation for the next piece of content.
Maybe the logic is trying to get the contents of the next non-existing paragraph. But some investigation from the engineers may help to clarify.

@Pginer-WMF I can replicate the issue

created T283513

@Pginer-WMF since the latest issue @Jpita reported, is being tracked in a different ticket (T283513) and there is no other pending issue for this task, I think that this ticket is not relevant anymore and can be closed.

Change 699785 had a related patch set uploaded (by Nik Gkountas; author: Nik Gkountas):

[mediawiki/extensions/ContentTranslation@master] SX: Fix calculation of section number for publishing and add tests

https://gerrit.wikimedia.org/r/699785

Change 699785 merged by jenkins-bot:

[mediawiki/extensions/ContentTranslation@master] SX: Fix calculation of section number for publishing and add tests

https://gerrit.wikimedia.org/r/699785