When upgrading WordPress core, theme, language or plugin – the update downloads successfully but leaves a blank upgrade screen, the page stops loading, you may be stuck in maintenance mode (requiring manual removal of .maintenance) and overall the upgrade never completes.
- Using WordPress version 4.x
- Accessing the WordPress site via HTTP (not HTTPS)
- When upgrading, I saw WordPress downloaded the zip file via HTTPS
- Using WordPress.com Jetpack (not sure if related or not)
- Google returns very few results describing the problem well.
I’ve tested this against four WordPress sites now and it appears to have successfully worked around the problem.
I installed a self-signed SSL certificate against the WordPress site using Server Name Indicator (SNI). Remember no dedicated IP is required when using SNI but it need a compatible server. For convenience I’ve used SSL certificates from tinycert.org.
Now when I access the site over HTTPS:
- Login again – note SSO with untrusted certificate will not work, you must use local site login credentials
- Perform the upgrade – it completes successfully and does not result in a blank or stalled upgraded screen.
Do you see another pattern? Isolated it to a version, Jetpack or another update? Please let me know!
Other Possible Causes
The above resolved my issue, but similar issues include:
- Installing WordPress via SSH Command Line
- My Dark Neon (Green) WordPress Theme
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- Moving From No Control Panel Servers to a cPanel Server
- How to delete ASP.NET temporary files from shared server
- Firefox Google Search Plugin for Australia (AU)
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- Simple IP Information / IP to Location (Country) Lookup