Adding Firewall through WUI hangs

When adding a device through the Web GUI, hangs at:

"Adding host host.domain.com community LALALAND port 161"

(highlighted in blue)

Adding the same host works through the CLI with:
cd /opt/observium
./add_device.php host.domain.com LALALAND v2c

We're at revision 0.14.8.5753.