OpenMediaVault 3.0.99 install Plugins shows Error

Lastest OpenMediaVault 3.x is V3.0.99, because OpenMediaVault 4.x do not support iscsi, this issue from debian , the omv official public the news about iSCSI EOL in OMV V4.

In order to test VM HA function, I need iSCSI, made me choose OMV 3.0.99 .
When I install iscsi-target plugin, it shows the error message as below.
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Reading package lists…
Building dependency tree…
>>> *************** Error ***************
Failed to execute command ‘export PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin; export LANG=C; export DEBIAN_FRONTEND=noninteractive; apt-get –yes –force-yes –fix-missing –allow-unauthenticated –reinstall install openmediavault-iscsitarget 2>&1’ with exit code ‘100’: Reading package lists…

Building dependency tree…

Reading state information…

Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
openmediavault-iscsitarget : Depends: linux-headers-amd64 but it is not going to be installed or
linux-headers-armel but it is not installable or
linux-headers-armhf but it is not installable or
linux-headers-i386 but it is not installable or
linux-headers-mips but it is not installable or
linux-headers-mipsel but it is not installable or
linux-headers-powerpc but it is not installable or
linux-headers-ppc64el but it is not installable or
linux-headers-s390 but it is not installable or
linux-headers-s390x but it is not installable or
linux-headers-sparc but it is not installable
E
:
Unable to correct problems, you have held broken packages.

<<< *************************************

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It’s just one command to fix this.
apt-get install -t -y jessie-backports linux-{image,headers}-amd64
Then install the iSCSI-target plugin again.