# ArgumentError (Attributes per element limit exceeded) when trying to open the diff of a locked topic

**URL:** https://meta.discourse.org/t/argumenterror-attributes-per-element-limit-exceeded-when-trying-to-open-the-diff-of-a-locked-topic/208090
**Category:** Bug
**Created:** [November 3, 2021, 9:43am UTC](https://meta.discourse.org/t/argumenterror-attributes-per-element-limit-exceeded-when-trying-to-open-the-diff-of-a-locked-topic/208090 "2021-11-03T09:43:40Z")
**Posts on this page:** 1
**Showing post:** 10

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### Author: ![zogstrip](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/zogstrip/32/512781_2.png) [@zogstrip](https://meta.discourse.org/u/zogstrip)
#### Post date: [June 22, 2026, 8:58am UTC](https://meta.discourse.org/t/argumenterror-attributes-per-element-limit-exceeded-when-trying-to-open-the-diff-of-a-locked-topic/208090/10 "2026-06-22T08:58:07Z")

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Closing this one as the discussion continues over at

> [@Backend 502/504 Timeout when saving major edits to long posts (~100k words) due to Diff bottleneck](https://meta.discourse.org/t/backend-502-504-timeout-when-saving-major-edits-to-long-posts-100k-words-due-to-diff-bottleneck/405773):
>
> When editing and saving extremely long posts (around 100,000 characters), we encountered a backend timeout issue. The server becomes unresponsive during the save operation, resulting in 502/504 errors. The frontend console shows the following error stack: ajax-error.js:36:15 l ajax-error.js:36 u ajax-error.js:75 d ajax-error.js:84 Ember 41 update rest.js:72 update rest.js:72 save rest.js:115 editPost composer.js:1147 Ember 6 I performed some comparative tests which suggest the bottleneck is in…

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_[View the full topic](https://meta.discourse.org/t/argumenterror-attributes-per-element-limit-exceeded-when-trying-to-open-the-diff-of-a-locked-topic/208090)._