Raspistill/camerapi doesn't work inside node-red


Apologies if this is in the wrong place, i'm new to the node-red community.

A few days ago i installed the camerapi node and i got it working. i don't rememeber changing anything on the pi but now it just outputs an empty string. I've also tried running the "raspistill ... " command using exec node and it returns an error code 255, yet the same command works when directly entered in the pi's terminal.

my first thought is that node-red doesn't have the permissions to run the commands but then the camerapi node wouldn't have worked before.
does anyone know why this is happening and has a possible solution?