OLA stops working. No respond on port 9090

I’m using RPi3 controlling my lights with OLA on port 9090 through an Enttec usb dmx controller.
Yesterday suddenly without executing any changes, lights fail to work.
No DMX signal was sent to controller and after investigation it seems OLA isn’t working. Using a newtork port scanner port no response on port 9090.
I re-installed OLA; same issue.
I tested with a spare RPi4 with an old config and there everything works.
What could be the cause of OLA failing on the RPi3 and how can I resolve it?
I can move all OH2 config to the RPi4, but this seems much more work then resolving the OLA issue…
Also I put the SD card from the RPi3 into the RPi4 and I get exact the same issue.
Buttom line:
RPi3, OH2, OLA can’t be reached.
RPi4, Other config of OH2, OLA can be reached. LED’s are working.
SD card from RPi3 onto RPi4, OLA can’t be reached.
So it must be a config issue and not a hardware issue.

Thx for the support.

Not sure I understand how you come to conclude that OLA failed.
The chain (and it is a one way chain) goes like that:
OH2 --> DMX binding --> LAN --> OLA --> DMX dongle --> DMX device
You write that no DMX signal was sent to the controller (meaning OLA, I assume), but that would mean that the binding (or your config) broke.
Did you try to go to web-interface: your-ip:9090, if you do not get any response, your OLA is down, if you do get a response, try to use the DMX mixer to verify that you can control your devices.
You can also get QLC+ a software DMX controller and communicate to your OLA devices, to make sure that they can receive commands via the lan. If that works too, the error is somewhere on the OH2 side, if not, the results from above would give you pointers for follow-up.

If it is really your OLA installation, I would just flash a new card and re-install.

Hi Markus,
Thx for your response!
The web-interface: my-ip:9090, does not get any response, so OLA is down.
You’re right, it’s my OLA installation,
You recommend to “just flash a new card and re-install”, but OLA and OH2 are installed on the same SD-card on the RPi, so I can’t just flash a new card.
I uninstalled OLA and reinstalled it, but this doesn’t solve the problem.
Any other idea?

I just noticed that a “warm welcome to the forum” is actually in order. Glad that you found your way here…
You seem to have a rpi3 and rpi4, there is a benefit of separating things on different physical devices if you can. For more powerful machines you can use virtualization but for raspberries, I prefer different devices.
If that is not an option you need to start digging through the various log-files, start-up messages and similar.
In addition look at the --purge option when using apt-install. This may help you deleting any config files that are messed up.
Lastly, and surely not something you want to hear, SD-card failures often start with some weird behaviors that cannot really be explained otherwise.
I hope you have backups, if not, now is as good a time as any.

Hi Markus,

Thanks for your reply!
I have a back-up of the config files (I used Visual Studio) and as we speak I’m re-installing a fresh OH + OLA to another SD-Card.
I hope I can restore the config files in “next-next-finish” style and get my home lights up&running again.
Keep you posted.