Preset and web Ui dowsn't load after reboot

I created a preset in MODEP that I want to use to trigger samples via Samplv1 using a MIDI footswitch. I loaded three samples into the library and assigned a snapshot to each sample, which I then trigger using a footswitch set to momentary mode

example:
switch 1 – momentary – group A: PC 0 + NoteOn 60 / vel 100
group B: NoteOff 60 / vel 0

switch 2 – momentary – group A: PC 1 + NoteOn 60 / vel 100
group B: NoteOff 60 / vel 0

switch 3 – momentary – group A: PC 2 + NoteOn 60 / vel 100
group B: NoteOff 60 / vel 0

This worked fine at first, but after rebooting the Raspberry Pi, the preset no longer loads and I also can’t access it via the web UI anymore.
Access via VNC and SSH still works.

What can I do now? Any help is appreciated!

Check the troubleshooting steps, take a look at the logs to see whether you see any significant problems: