Using latest firmware as of Oct 2015: 5.20.99 Release 1108
When creating a Link Aggregation Dynamic LACP from the station connected to the soon-to-be created Aggregated ports (trunk). The new aggregated interface does not receive a "port link-type" and thus fails. You loose ability to continue configuring the switch through the web interface. Also may want to set a static IP on the switch if the dhcp server is behind the soon-to-be-created Aggrigation link.
Two ways to get around this issue are either:
a) configure the bridge from on a non-bridged port from another workstation. And then go to Port Management=>Setup=>Link Type=>[choose one]=>Apply
b) download the config file, edit it, upload it, reboot.
The config file should with working Aggregation looks like this:
=== snip ===
stp enable
#
interface Bridge-Aggregation1
port link-type access
link-aggregation mode dynamic
#
interface NULL0
=== ...fold... ===
#
interface GigabitEthernet1/0/47
port link-type hybrid
port hybrid vlan 1 untagged
port auto-power-down
poe enable
stp edged-port enable
port link-aggregation group 1
#
interface GigabitEthernet1/0/48
port link-type hybrid
port hybrid vlan 1 untagged
port auto-power-down
poe enable
stp edged-port enable
port link-aggregation group 1
#
=== /snip ===
A config file with a broken Aggregation looks like this and contains no "port link-type ..." entry:
=== snip ===
stp mode rstp
stp enable
#
interface Bridge-Aggregation1
link-aggregation mode dynamic
#
interface NULL0
=== /snip ===
HP needs to patch the switch so that it defaults to some form of "port link-type" when Aggregation is first enabled.