Hello everyone,
I currently have to maintain a Flow from a colleague and have to admit that I'm just a beginner and don't really know how everything works yet.
The said Flow suddenly stopped working a week ago without any changes made.
The Error message is

The Flow part is

and the code in 'File Path' is
last(split(outputs('Element_von_SPL_Rechnungsfreigabe_abrufen')?['body/Rechnungspfad'],'/'))
A week ago it looked like this

I can't share everything because of the data security but the path in this part is correct

Unfortunately I didn't get a documentation or anything but the flow is responsible to sent invoices to different colleagues who have to approve/deny the process.
But now it always stops when it saves the invoice to the sharepoint (I think).
The whole flow looks like this



Could someone assist me?
Maybe it's a known problem but I don't really get why there is suddenly a 'null' error.
Kind regards
Ariini