Topic: Cannot load PianoTeq

Hello everyone,
since a few month Iḿ a proud user of PianoTeq.
I play it using Zynthian, a RaspberryPi (V4) engine. I have two of them.

Now I cannot load PianoTeq in one device. The load-process stops without loading.
Zynthian uses a web-configuration tool.
That says 500: Internal Server Error

The other device works perfectly. But it's the same configuration.
Who can help?