Read-only file system error accessing Mailman admin

When I try to access the pending-admin page for my Mailman list (from outside of cPanel), viz.,

HTML:

http://mydomain.tld/mailman/admindb/discuss_mydomain.tld

I get (after authenticating with the moderator password) the following (noninformative) error:

When I look in the Mailman error log, the most-relevant entry seems to be:

Code:

OSError: [Errno 30] Read-only file system: '/usr/local/cpanel/3rdparty/mailman/archives/public/discuss_mydomain.tld’

The traceback is:

Code:

Traceback (most recent call last):
admin(4753):   File "/usr/local/cpanel/3rdparty/mailman/scripts/driver", line 117, in run_main
admin(4753):     main()
admin(4753):   File "/usr/local/cpanel/3rdparty/mailman/Mailman/Cgi/admindb.py", line 337, in main
admin(4753):     mlist.Save()
admin(4753):   File "/usr/local/cpanel/3rdparty/mailman/Mailman/MailList.py", line 607, in Save
admin(4753):     self.CheckHTMLArchiveDir()
admin(4753):   File "/usr/local/cpanel/3rdparty/mailman/Mailman/Archiver/Archiver.py", line 236, in CheckHTMLArchiveDir
admin(4753):     breaklink(pubdir)
admin(4753):   File "/usr/local/cpanel/3rdparty/mailman/Mailman/Archiver/Archiver.py", line 56, in breaklink
admin(4753):     os.unlink(link)
admin(4753): OSError: [Errno 30] Read-only file system: '/usr/local/cpanel/3rdparty/mailman/archives/public/discuss_mydomain.tld'

Notably, I do not get an error when I access the same page via cPanel, i.e., with a URL like:

HTML:

https://myprovider.tld:2083/cpsess0123456789/3rdparty/mailman/admin/discuss_mydomain.tld/

First, I note that the particular fact pattern (viz., error from outside of cPanel, but no error from inside cPanel) is identical to that reported in:
Copy mailman settings and subscribers.
However, the identification of "[Errno 30] Read-only file system" and associated traceback is different than identified there.

To be clear: This Mailman installation is not on a remote server. It's just the same one installed with cPanel. (FWIW, I did migrate this list from another server.)

Here's what I've already done:

Code:

/scripts/fixmailman
/scripts/restartsrv_mailman --stop
/scripts/restartsrv_mailman --start

and

Code:

/usr/local/cpanel/3rdparty/mailman/bin/check_perms

with the output:

Code:

Warning: Private archive directory is other-executable (o+x).
This could allow other users on your system to read private archives.
If you're on a shared multiuser system, you should consult the
installation manual on how to fix this. 

I'd appreciate any help in resolving this.

Thanks!

 

Michael:
1) Yes, the Experimental option WAS enabled (even though it said that disabled was the default—Looking over my notes from when I set this server up, for some reason I elected to change the default by enabling this option).
2) I disabled this option and SAVE-d.
3) Success! I can now reach those pages (from external to cPanel).

You said "temporarily disabling this option." Should I just leave it disabled and announce victory? Or are you suggesting that there's a good reason to leave it enabled.

Thanks!

 

Thanks, Michael! My problem is now solved.