In Discourse 3.1.0.beta5, users encountering the ‘Unsupported browser’ splash screen on desktop (e.g., SeaMonkey 2.53.16) face a critical usability bug: the page does not scroll. This occurs because overflow-y: hidden is set initially for the splash screen, but JavaScript fails to remove it due to errors in unsupported environments. The root cause is the use of the CSS revert value (e.g., overflow-y: revert !important;), which is not widely supported in older browsers ValdikSS. ValdikSS suggests replacing revert with initial for better compatibility. While JammyDodger questions whether this is expected behavior for unsupported browsers, ValdikSS clarifies that the unsupported version should still be readable — and the lack of scrolling breaks that expectation. The issue also affects crawlers and archiving services like Wayback Machine. Falco requested browser details, which ValdikSS provided as SeaMonkey 2.53.16, the latest available version of that browser. This is confirmed as a bug needing a fix to ensure basic accessibility even in unsupported modes.
Discourse 3.1.0.beta5.
When the website is loaded in unsupported desktop browser (or, I assume, gets crawled as well), the page does not scroll.
This is due to initial overflow-y: hidden set for the splash screen, but due to JS errors and such, the “application” never gets started and never receives the chance to remove the attribute.
First bad commit is
https://github.com/discourse/discourse/commit/526115f11a9313c079c230c1d7359c865607115e
Would this not be one of the consequences of it being an unsupported browser?
This version is supposed to be read-only, but you can’t read since there’s no scrolling. I assume the same issue applies when it’s being saved by Wayback Machine, crawlers, etc.
This is a bug.
The issue is caused due to usage of relatively new revert option of CSS, which is not widely supported by outdated browsers.
overflow-y: revert !important;
Consider using initial instead of revert.
What is the browser and version where this happens?
SeaMonkey 2.53.16, the latest one.