Error when installing docker

Error #0:
OMV\ExecException: Failed to execute command 'export PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin; export LANG=C; omv-mkconf apt 2>&1' with exit code '1': Warning: apt-key output should not be parsed (stdout is not a terminal)
Executing: /tmp/apt-key-gpghome.FoazplMMaW/gpg.1.sh --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 9dc858229fc7dd38854ae2d88d81803c0ebfcd88
gpg: cannot open '/dev/tty': No such device or address
run-parts: /usr/share/openmediavault/mkconf/apt.d/15omvextras exited with return code 2 in /usr/share/php/openmediavault/system/process.inc:182
Stack trace:
#0 /usr/share/openmediavault/engined/module/apt.inc(37): OMV\System\Process->execute()
#1 /usr/share/openmediavault/engined/rpc/config.inc(168): OMVModuleApt->applyConfig()
#2 [internal function]: OMVRpcServiceConfig->applyChanges(Array, Array)
#3 /usr/share/php/openmediavault/rpc/serviceabstract.inc(123): call_user_func_array(Array, Array)
#4 /usr/share/php/openmediavault/rpc/rpc.inc(86): OMV\Rpc\ServiceAbstract->callMethod('applyChanges', Array, Array)
#5 /usr/share/openmediavault/engined/rpc/omvextrasorg.inc(95): OMV\Rpc\Rpc::call('Config', 'applyChanges', Array, Array)
#6 [internal function]: OMVRpcServiceOmvExtras->setRepo(Array, Array)
#7 /usr/share/php/openmediavault/rpc/serviceabstract.inc(123): call_user_func_array(Array, Array)
#8 /usr/share/php/openmediavault/rpc/rpc.inc(86): OMV\Rpc\ServiceAbstract->callMethod('setRepo', Array, Array)
#9 /usr/sbin/omv-engined(536): OMV\Rpc\Rpc::call('OmvExtras', 'setRepo', Array, Array, 1)
#10 {main}