[Windows] Connection problems with Enttec OpenDMX USB Interface

[alessandrocaseti]

Describe the bug
QLC has some issues in connecting my Enttec OpenDMX USB interface. If the device is plugged in, QLC won't start at all. If disconnected, it will start but as soon as I plug the cable in it immediatly crashes. This only happens in version >= 4.13.0. I haven't tried on V5 but since it isn't stable I can't use it for my current projects. I tried 4.12.7 and had no issues at all.

To Reproduce
Steps to reproduce the behavior:

1. Insert Enttec OpenDMX USB interface
2. Open QLC Version >= 4.13.0
3. Disconnect Enttec OpenDMX USB interface
4. Re-open QLC and plug in the cable again

Temporary solution
From the forum, I found a temporary solution:

1. Open Device Managment
2. Disable and re-enable the device under USB Controllers
3. Quickly open QLC

Desktop (please complete the following information):

• OS: Windows 11 Version 23H2
• QLC+ Version 4.13.1

Additional context
This bug has been reported from other users and additional context can be found here:
https://www.qlcplus.org/forum/viewtopic.php?t=17163
https://www.qlcplus.org/forum/viewtopic.php?t=17960
https://www.qlcplus.org/forum/viewtopic.php?t=17370
https://www.qlcplus.org/forum/viewtopic.php?t=18044

[mcallegari]

What we know about this so far:

• Happens only on Windows
• Doesn't happen on every Windows machine
• Doesn't happen at every startup
• QLC+ 4.13.0 and higher has switched to a 64bit build. Compared to 32bit, one file needed to be added to the deploy: ftd2xx64.dll
• Some users fixed the issue by installing the FTDI driver from ENTTEC and removing duplicate DLL (this post)
• the installed DLL comes from the official D2XX package version v2.12.36.4
• I am personally not able to reproduce the crash. All the Windows instances that I tested worked out of the box (even PCs that never saw QLC+ before)

[alessandrocaseti]

@mcallegari any news on this? Is there any chance that this issue is related to #1656 ?

[mcallegari]

@mcallegari any news on this? Is there any chance that this issue is related to #1656 ?

No

[leonreucher]

Same issue here - tried on two Win 11 machines, driver was reinstalled several times - but with the interface connected, QLC won't start. When the interface is connected after the program start, the software crashes.

[mcallegari]

We involved ENTTEC and they cannot reproduce the issue either on two Windows 11 machines.

[alessandrocaseti]

@mcallegari the weird thing is that, in my case, it started to happen only in december. Before than, i used another open-DMX interface (worked without any issues), that got killed by a voltage surge. When trying the new one, it worked well but only for 1 time. The second time opening it it started giving issues (the PC is alsways the same). Is there any log file that I can share when I try to open the app with the interface connected?

[mcallegari]

@alessandrocaseti can you please confirm if you are using an original Enttec Open DMX or a clone?
There's a lot of fake FTDI chips on the market and I suspect the driver rejects them with unexpected outcomes.

[alessandrocaseti]

@alessandrocaseti can you please confirm if you are using an original Enttec Open DMX or a clone?
There's a lot of fake FTDI chips on the market and I suspect the driver rejects them with unexpected outcomes.

Yes, i confirm. The interface is undoubtedly original.

[acotam2]

Windows 11 24H2 x64, QLC+ 4.14.0, CDM212364 driver from FTDI Website, both fake and real FTDI chip based adapters, cannot reproduce
same with windows 7 SP1 x64, QLC+ 4.13.1, same drivers, same adapters, also cannot reproduce.

BTW drivers from enttec website are identical to CDM212364 from FTDI website, checksums of files used are identical: ftd2xx64.dll, ftser2k.lib, ftcserco.dll, ftserui2.dll checked.