Failed to upgrade to Virtualmin Pro : Failed to write to /usr/sbin/virtualmin : Bad file number

Issue is a blocker for our deployment.

We have a Virtualmin license for 10 domains/1 server. Our host is Joyent. Virgin installation as host delivers. Attempt to upgrade to Virtualmin Pro from within interface fails with the following output:

------------------------

Upgrade to Virtualmin Pro
Creating Virtualmin license file ..
.. done
Downloading and installing modules ..
Installing virtual-server version 3.60 ..
Downloading http://software.virtualmin.com/wbm/virtual-server-3.60.wbm.gz (3098302 bytes) ..
Received 1024 bytes (0 %)
Received 310272 bytes (10 %)
Received 620544 bytes (20 %)
Received 929792 bytes (30 %)
Received 1240064 bytes (40 %)
Received 1549312 bytes (50 %)
Received 1859584 bytes (60 %)
Received 2168832 bytes (70 %)
Received 2479104 bytes (80 %)
Received 2789376 bytes (90 %)
Received 3098302 bytes (100 %)
.. download complete.
Failed to upgrade to Virtualmin Pro : Failed to write to /usr/sbin/virtualmin : Bad file number

Status: 
Closed (fixed)