Unable to Delete Themes / Update Plugins - Additional commonL10n Issues

[codesmith32]

I'm having a ton of issues using the admin (updating plugins, deleting themes), and they all appear to stem from commonL10n not being defined in the JS. Here are the errors I'm seeing in the console when I load any admin page:

jQuery.Deferred exception: commonL10n is not defined @https://example.com/wp-admin/js/common.min.js?ver=5.8:2:14762

jQuery.Deferred exception: window.authcheckL10n is undefined @https://example.com/wp-includes/js/wp-auth-check.min.js?ver=5.8:2:433

Uncaught ReferenceError: commonL10n is not defined: @https://example.com/wp-admin/js/common.min.js?ver=5.8:2:14762

Uncaught TypeError: window.authcheckL10n is undefined: @https://example.com/wp-includes/js/wp-auth-check.min.js?ver=5.8:2:433

I did do some research and found that it appears commonL10n was removed? #51123
Was it really accidentally left in so many core files?
I did upgrade my WP install from WP 5.4 to 5.8. Is it possible it didn't upgrade these files or something? And if so, perhaps the update procedure is broken?

[codesmith32]

Upon further review, it may be a caching issue.

For some reason, I'm unable to get my browser to reload the new core js files, even with force-refresh. With that said, when viewing the files on the server, they do appear different.

The site is having SSL issues, which is likely preventing the force-reload.

If it does work fine after the SSL issues are resolved (which is likely), I'll return and mark the bug resolved.

[swissspidy]

Those variables were indeed removed, but #51123 restored them for backward compatibility. So yeah, this sounds like some caching issue or broken update on your side.

[codesmith32]

Confirmed: After the SSL issues were resolved, and things loaded again, I no longer have these commonL10n issues. Thus, it was definitely a caching issue.

[SergeyBiryukov]

Thanks for the follow-up!