hey i have looking in the forum old answers for cron but cant for the life of get this working. i have done exactly same thing on my x64 machine line by line and it is working there.
i have a program i want to start on boot its in /home/dietpi/ccminer/ my script is call mine.sh
And it works
it start minening when i do ./mine.sh
then i go crontab -e put the line
@reboot /home/dietpi/ccminer/mine.sh
save and exit
but when i reboot nothing start
do you have some ideas?
what is the user you are using to run crontab -e? is it root user? or something else?
the user is both root and dietpi i tried both
Can you show your crontab and the content of the script mine.sh?
So I counted the lines in your crontab 
It read 25 lines but your last line is your entry.
Crontab needs that each entry ends with a newline character.
Go to the end of your entry, hit Return and save and try again.
im sorry that that did not work
A couple of things, there is no shebang on the header of the script, and when you create scripts you should either use the full path or specify the PATH environmental variable.
correct, the program ccminer to be called with full path from inside the script