just came across this thread -- here's the fix:
a. in udev rules, make sure the command is on a single line (see udev - Debian Wiki) before the backslash ('\') e.g.
Code
IMPORT{builtin}="blkid" ACTION=="add", SUBSYSTEM=="block", KERNEL=="sda*", ENV{ID_FS_USAGE}=="filesystem", \
RUN+="/usr/bin/systemd-run /storage/autoplay.sh /dev/%k"The original code in the thread pastes into several lines -- this is what caused boot loop most likely.
b. the autorun.sh needs to start with #!/bin/sh -- otherwise systemd fails to run it. Thing is, this vital line was eaten by the forum parsing code. Try posting a code block here starting with '#'