Steps to replicate the issue (include links if applicable):

When a Timeline bar crosses June in a timeline that starts before June, this mostly happens to pages with timelines crossing June 2026 as they are recently updated. All timelines that are complete or beyond June work as intended.

Examples of pages affected by bug as of June 3, 2026:

https://en.wikipedia.org/wiki/Template:List_of_presidents_of_the_Philippines_timeline

https://en.wikipedia.org/wiki/Tropical_cyclones_in_2026#Summary

https://en.wikipedia.org/wiki/2026_Pacific_typhoon_season#Seasonal_summary

https://en.wikipedia.org/wiki/Template:List_of_presidents_of_the_Philippines_timeline

What happens?:

It generates this error message in Red text: "Timeline error. Could not store output files"

What should have happened instead?:

It should have generated a timeline as it normally should. Example: https://en.wikipedia.org/wiki/Tropical_cyclones_in_2019#Summary

Software version (on Special:Version page; skip for WMF-hosted wikis like Wikipedia):

EasyTimeline 1.90

Other information (browser name/version, screenshots, etc.):

It affects all users and visitors of the pages.

Discussion from one of the pages affected:
https://en.wikipedia.org/wiki/Talk:Tropical_cyclones_in_2026#h-Timeline_error-20260602014100