Thank you for the information @wpcheetah
Since deactivating and reactivating FDP recreates the file, this doesn’t look like a permanent permissions issue. It looks like something removes the file after it was successfully created.
FDP only deletes that file when:
- FDP is deactivated
- FDP is updated (replaces the old file with a new one)
It never deletes it during normal use.
The most common reasons it disappears again after several days:
- An automatic FDP update (WordPress background updates) refreshed the mu-plugin and the copy failed once (less probable)
- A security plugin removed the file during a scheduled scan
- Your host’s malware scanner removed it
- A deployment/sync overwrote the site without including
wp-content/mu-plugins/
To help us pinpoint it, please check:
- Is auto-update enabled for plugins? (Dashboard → Plugins, or via host panel)
- Do you use Wordfence, Sucuri, MalCare, or similar? Check quarantine logs for
eos-deactivate-plugins.php
- Who is your host?
- Do you deploy from Git/staging on a schedule?
- When did it last happen, was there an FDP update around that time?
Workaround until we find the cause:
If a security plugin is involved, whitelist that path/file.
If you use deployments, add the mu-plugins file to your deploy process.
I hope it helps
Have a great day!
Jose
Thanks,
The only security plugin I’m using is Jetpack protect, I’m hosting on my own VPS. Auto-update is enabled, I also use MainWP. I don’t use GIT or staging.
It seems to happen after an update, I have other files in mu folder that don’t get deleted, it’s only FDP.
You are welcome @wpcheetah
So, this is almost certainly FDP’s own update process, not a permissions issue, Jetpack, or a generic cleanup of the mu-plugins directory.
We’ve fixed the issue in v. 2.6.8, which includes a safer installation process with an automatic retry mechanism.
You may experience the same issue one more time when updating to the next version, because the current FDP update code will still be used for that update. After that, the new update process will be in place, so the issue should no longer occur in future updates.
Thanks for the detailed info. It helped us pinpoint the exact cause.