> For the complete documentation index, see [llms.txt](https://docs.holoplot.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.holoplot.com/user-guides/troubleshooting.md).

# Troubleshooting

Welcome to our Troubleshooting FAQs page. Here, you'll find answers to common questions and solutions to issues you may encounter while configuring, operating and maintaining a HOLOPLOT sound system.

### Known issues

<table data-view="cards" data-full-width="true"><thead><tr><th>Issue Summary</th><th>Description</th><th>Affected Software<select multiple><option value="K45mwCJYG3sU" label="HOLOPLOT Control" color="blue"></option><option value="YQEfmFxkAfaX" label="HOLOPLOT OS" color="blue"></option><option value="WE1TtSE7ISCg" label="HOLOPLOT Plan" color="blue"></option></select></th><th>Affected version</th><th>Status<select><option value="Tmd4fcESUMBY" label="Open" color="blue"></option><option value="xZoX1RbtvaFz" label="Closed" color="blue"></option></select></th><th>Workaround</th><th>Resolution</th></tr></thead><tbody><tr><td><strong>HOLOPLOT Control temporarily unresponsive</strong></td><td>When a Controller loses power, HOLOPLOT Control on the remaining Controllers can show a Gateway Timeout or not respond for up to about 2 minutes, until the system has detected the lost Controller. The Controller cluster automatically recovers and continues to work with two out of three nodes. Audio playback continues uninterrupted, and Processors and modules are not affected.</td><td><span data-option="K45mwCJYG3sU">HOLOPLOT Control, </span><span data-option="YQEfmFxkAfaX">HOLOPLOT OS</span></td><td>2.6.2, 2.6.3</td><td><span data-option="Tmd4fcESUMBY">Open</span></td><td>No action needed. HOLOPLOT Control responds again on its own.</td><td>Improved in 2.6.3: Processor audio is no longer interrupted and no Processor failover is triggered when a Controller goes offline. Under investigation</td></tr><tr><td><strong>Control link temporarily reported as "Unknown" after a network disconnect</strong></td><td>When the active control network connection (primary or secondary) to an audio module is disconnected, the module may temporarily report its control link state as "Unknown" until it re-establishes communication over the other control network link. During this transition, the connection between HOLOPLOT Control and the module may be interrupted.</td><td><span data-option="K45mwCJYG3sU">HOLOPLOT Control, </span><span data-option="YQEfmFxkAfaX">HOLOPLOT OS</span></td><td>2.6.2, 2.6.3</td><td><span data-option="Tmd4fcESUMBY">Open</span></td><td>No action needed. Audio playback continues uninterrupted while the module re-establishes its control link.</td><td>Improved in 2.6.3: the module re-established communication after about 6 seconds in HOLOPLOT's testing, compared with 26 seconds on 2.6.2</td></tr><tr><td><strong>Inconsistent pairing and power status display</strong></td><td>In rare cases, the Devices and Module Pairing pages in HOLOPLOT Control may display inconsistent module pairing and power status, showing modules as unpaired and sleeping while they are actually offline or removed.</td><td><span data-option="K45mwCJYG3sU">HOLOPLOT Control, </span><span data-option="YQEfmFxkAfaX">HOLOPLOT OS</span></td><td>2.6.2</td><td><span data-option="xZoX1RbtvaFz">Closed</span></td><td>–</td><td>Fixed in 2.6.3</td></tr><tr><td><strong>Reconnect dialog does not reconnect after a Controller goes offline</strong></td><td>When the Controller that HOLOPLOT Control is connected to goes offline (fatal failure, power-off or reboot), the reconnect dialog lists the remaining Controllers, but selecting one can fail to reconnect HOLOPLOT Control. Audio playback continues uninterrupted.</td><td><span data-option="K45mwCJYG3sU">HOLOPLOT Control, </span><span data-option="YQEfmFxkAfaX">HOLOPLOT OS</span></td><td>2.6.3</td><td><span data-option="Tmd4fcESUMBY">Open</span></td><td>Open HOLOPLOT Control at the address of another Controller. If it is not available immediately, it will be within about 2 minutes after the Controller went offline. The Public System API may remain available during this time, depending on which Controller the venue control system is connected to. Consider having the venue control system try the other Controllers in turn.</td><td>Under investigation</td></tr><tr><td><strong>Modules temporarily lose control after a Controller goes offline</strong></td><td>When a Controller goes offline (fatal failure, power-off or reboot), some modules that were connected to it have to reconnect their control communication to another Controller. HOLOPLOT Control shows these modules as offline until they have reconnected, which can take up to about 4 minutes. Until then, an affected module does not follow control changes, such as a mute, from HOLOPLOT Control or the Public System API. This can also affect a module that HOLOPLOT Control shows as online.</td><td><span data-option="K45mwCJYG3sU">HOLOPLOT Control, </span><span data-option="YQEfmFxkAfaX">HOLOPLOT OS</span></td><td>2.6.3</td><td><span data-option="Tmd4fcESUMBY">Open</span></td><td>No action needed. Audio playback continues uninterrupted, and the Controller cluster resolves this automatically.</td><td>Under investigation</td></tr><tr><td><strong>Monitoring temporarily unreliable after a Controller goes offline</strong></td><td>When a specific Controller goes offline (fatal failure, power-off or reboot), some monitoring services can be unreliable for up to about 3 minutes. During this time, HOLOPLOT Control can keep showing the lost Controller as online, show some modules as offline, and show unreliable or no metering for some modules.</td><td><span data-option="K45mwCJYG3sU">HOLOPLOT Control, </span><span data-option="YQEfmFxkAfaX">HOLOPLOT OS</span></td><td>2.6.3</td><td><span data-option="Tmd4fcESUMBY">Open</span></td><td>No action needed. Audio playback continues uninterrupted, and the Controller cluster resolves this automatically.</td><td>Under investigation</td></tr><tr><td><strong>Controller shown offline after a reboot</strong></td><td>In rare cases, after a Controller reboot, HOLOPLOT Control can show that Controller as offline although it is up and running. Display issue only.</td><td><span data-option="K45mwCJYG3sU">HOLOPLOT Control, </span><span data-option="YQEfmFxkAfaX">HOLOPLOT OS</span></td><td>2.6.3</td><td><span data-option="Tmd4fcESUMBY">Open</span></td><td>–</td><td>Under investigation</td></tr><tr><td><strong>Manual failover to an unhealthy Processor is reverted immediately</strong></td><td>Automatic failover is triggered when the active Processor's health is worse than Warning, but HOLOPLOT Control allows a manual failover to a Processor in an Error state. After a manual failover to such a Processor, the system immediately fails over automatically back to the healthy one. This applies in both directions, from Main to Backup and from Backup to Main.</td><td><span data-option="K45mwCJYG3sU">HOLOPLOT Control, </span><span data-option="YQEfmFxkAfaX">HOLOPLOT OS</span></td><td>2.6.3</td><td><span data-option="Tmd4fcESUMBY">Open</span></td><td>Unpair the healthy Processor before debugging or testing the unhealthy one.</td><td>Under investigation</td></tr><tr><td><strong>Short audio dropout when a Processor rebuilds its connection to the Controllers</strong></td><td>In rare cases, the active Processor has to fully rebuild its connection to the Controllers' internal messaging. It then reapplies its audio configuration, which can interrupt audio for up to about 2 seconds. Ordinary Controller outages and network interruptions do not cause this.</td><td><span data-option="YQEfmFxkAfaX">HOLOPLOT OS</span></td><td>2.6.3</td><td><span data-option="Tmd4fcESUMBY">Open</span></td><td>–</td><td>Under investigation</td></tr><tr><td><strong>Preset change lost while a Controller rejoins the cluster</strong></td><td>A preset change made in HOLOPLOT Control at the moment a Controller that was disconnected from the other Controllers rejoins the cluster can be lost without an error message.</td><td><span data-option="K45mwCJYG3sU">HOLOPLOT Control, </span><span data-option="YQEfmFxkAfaX">HOLOPLOT OS</span></td><td>2.6.3</td><td><span data-option="Tmd4fcESUMBY">Open</span></td><td>Check that the preset is active and change it again if needed.</td><td>Under investigation</td></tr><tr><td><strong>Processor starts its previous firmware on the first restart after an update</strong></td><td>On the first restart after a firmware update, a Processor starts its previous firmware version and is then switched back to the current version automatically. This delays start-up by about 2 minutes. Later restarts are not affected.</td><td><span data-option="YQEfmFxkAfaX">HOLOPLOT OS</span></td><td>2.6.3</td><td><span data-option="Tmd4fcESUMBY">Open</span></td><td>No action needed.</td><td>Fix in progress</td></tr></tbody></table>

### HOLOPLOT Control interface

<details>

<summary>Why can't I access HOLOPLOT Control on my browser?</summary>

If you experience issues with loading HOLOPLOT Control on your laptop or desktop that is connected to the HOLOPLOT system, walk through these steps:

{% hint style="info" %}
After a Controller loses power, HOLOPLOT Control can be unresponsive for up to about 2 minutes while the Controller cluster recovers (a known issue in HOLOPLOT OS 2.6.2 and 2.6.3). Wait for this window to pass before troubleshooting further. If the reconnect dialog does not reconnect, open HOLOPLOT Control at the address of another Controller.
{% endhint %}

1. Ensure the controller is powered and booted (fan revving up when powered?)
2. Press the power button behind the front grill if not booted yet
3. Confirm the Gigabit 1 port is connected to the switch/router
4. Confirm the laptop is on the same network
5. Confirm the controller can be accessed by typing in the IP address directly in the browser (run IP scan if necessary to determine IP)

A browser losing its connection to HOLOPLOT Control is not the same as the Controller being offline. For what HOLOPLOT Control itself reports about a Controller's status, see [Monitoring device health](/holoplot-control/maintaining-the-system/monitoring-device-health.md).

#### If the problem persists:

1. Confirm the iDRAC port is connected in case HOLOPLOT remote support is needed.
2. Confirm the network has an internet connection in case remote support is needed.

</details>

<details>

<summary>What should I do if the interface of HOLOPLOT Control appears empty?</summary>

If you cannot see some or any Modules in HOLOPLOT Control, check these parts:

1. Make sure the module is powered on.
2. Ensure the module is connected to the dedicated network, carrying a switch and router (DHCP server) through the primary Uplink port.
3. On Dante systems, check whether the module appears in Dante Controller and note its IP range. On [RAVENNA](/holoplot-control/configuring-the-system/network-settings-ravenna-only.md) systems, check the module in HOLOPLOT Control's Devices list and in [Stream Management](/holoplot-control/configuring-the-system/stream-management-ravenna-only.md).

</details>

### Configuring the system

<details>

<summary>What should be done if controllers cannot connect to the cloud due to a lack of NTP sync between controllers?</summary>

If you encounter issues with module status toggling between online/offline and your controllers cannot connect to the cloud due to a lack of NTP sync between controllers, follow these troubleshooting steps:

1. Check NTP status in HOLOPLOT Control: Open the Device List and look for an "NTP - Not Synchronized" health issue on the affected Controllers or Modules. See the [Device issues list](/holoplot-control/maintaining-the-system/device-issues-list.md) for what this issue means.
2. Check internet connection: Verify that your laptop has a wired internet connection.
3. Ping time servers: On your laptop, ping "time1.google.com" or "time.google.com" to ensure they are reachable.
4. Ensure Internet access: If any of the above points fail, ensure your setup has Internet access and is not blocked by firewall settings.
5. Check switch settings: Examine the switch settings to which Modules and controllers are connected. Confirm if IPv4 and/or IPv6 routing is disabled.
6. If routing is enabled, disable it on all relevant switches and restart all controllers.

Following these steps, you can troubleshoot and resolve issues related to module status toggling and cloud connection without NTP sync between controllers.

</details>

<details>

<summary>I have no sound coming from a specific module or array</summary>

If you have no sound coming from a specific module or array, walk through these steps to locate an issue:

#### Connection, hardware and 3rd party software components

1. Validate power to the module
   1. MD96:

      Validate power connector to the module and ensure rear display reads information.
   2. MD 80-S

      Validate Sub connections (Sublink Ethercon, Power EP and Power Sub Amplifier). Interconnections need to be established before booting the module otherwise it will come up as unset. If the module is in unset mode, proceed with next step.
   3. Power cycle the sub
2. Confirm network connections by scanning/pinging the module's IP address
3. On Dante systems, check Dante Controller for routing and critical events, and for audio input and output.
4. On RAVENNA systems, check [Stream Management](/holoplot-control/configuring-the-system/stream-management-ravenna-only.md) in HOLOPLOT Control for the same information.
5. Test network cables

#### HOLOPLOT configuration

1. Confirm a project is loaded and inputs assigned
2. Confirm health status (esp. temperature) & metering
3. Confirm overall system health
4. Check input metering
5. Check output metering, check Mute and Solo buttons
6. Validate signal path on per channel basis
7. Use the Signal Flow visualization in HOLOPLOT Control (see [Getting an overview of the active project](/holoplot-control/operating-the-system/getting-an-overview-of-the-active-project.md)) to trace the path from Audio Inputs to Beams to Modules.
8. If the system uses a HOLOPLOT Processor, check the Processor's health (DSP configuration, Audio Engine) in the Device List. See [Monitoring device health](/holoplot-control/maintaining-the-system/monitoring-device-health.md).

</details>

### Updating the system

<details>

<summary>What should I do if a device becomes stuck during an update?</summary>

Modules, Processors, and AudioBridges all have their firmware updated from the Controller (since HOLOPLOT OS 2.4.0). If you experience an issue when updating a device where the update is stuck:

1. Make sure your network is still hooked up to the internet.
2. Wait at least 2-3min.
3. If the problem persists, power cycle the device.
4. Observe the update process.

If the problem persists, contact <support@holoplot.com>

</details>


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