Ok, so I am up running with OMV 5.x. So far it works ok, but not great. This is understandable since this is a pre-release version.
For example there are no text or values under "System Information" in the dashboard tab (blank). Also pressing the Apply button after each change takes ages (this is not everything taking a long time).
But, the most important problem:
When trying to set up a datapool with the UnionFS plugin, it gives me this error when pressing save:
{"response":null,"error":{"code":0,"message":": Missing 'required' attribute 'self_mntentref'.","trace":"OMV\\Json\\SchemaValidationException: : Missing 'required' attribute 'self_mntentref'. in \/usr\/share\/php\/openmediavault\/json\/schema.inc:621\nStack trace:\n#0 \/usr\/share\/php\/openmediavault\/json\/schema.inc(395): OMV\\Json\\Schema->checkProperties(Object(stdClass), Array, '')\n#1 \/usr\/share\/php\/openmediavault\/json\/schema.inc(285): OMV\\Json\\Schema->validateObject(Object(stdClass), Array, '')\n#2 \/usr\/share\/php\/openmediavault\/json\/schema.inc(257): OMV\\Json\\Schema->validateType(Object(stdClass), Array, '')\n#3 \/usr\/share\/php\/openmediavault\/rpc\/paramsvalidator.inc(59): OMV\\Json\\Schema->validate(Object(stdClass))\n#4 \/usr\/share\/php\/openmediavault\/rpc\/serviceabstract.inc(179): OMV\\Rpc\\ParamsValidator->validate('{\"name\":\"l\",\"se...')\n#5 \/usr\/share\/openmediavault\/engined\/rpc\/unionfilesystems.inc(182): OMV\\Rpc\\ServiceAbstract->validateMethodParams(Array, 'rpc.unionfilesy...')\n#6 [internal function]: OMV\\Engined\\Rpc\\UnionFilesystems->set(Array, Array)\n#7 \/usr\/share\/php\/openmediavault\/rpc\/serviceabstract.inc(123): call_user_func_array(Array, Array)\n#8 \/usr\/share\/php\/openmediavault\/rpc\/rpc.inc(86): OMV\\Rpc\\ServiceAbstract->callMethod('set', Array, Array)\n#9 \/usr\/sbin\/omv-engined(537): OMV\\Rpc\\Rpc::call('UnionFilesystem...', 'set', Array, Array, 1)\n#10 {main}"}}
Did you got this message when setting up the plugin on your Rock64 board, @ryecoaaron?