Nth instance of character

[fog88]

Hello,

I've a problem with my syntax of nth instance of character.
This is my code :
hashcat -a 0 -m 0 hash.txt demonstration.dict -r test.rule --stdout

hash.txt containt MD5 hash of "pas$word"

demonstration.dict contain only one word : password

test.rule containt only this rule : %1s Dp ip$

I want to discover "pas$word" of hash. rule "ss$" replace all instance of 's' and give pa$$word.

nth instance of character rule is the solution with "%1s Dp ip$"

but when I execute : hashcat -a 0 -m 0 hash.txt demonstration.dict -r test.rule --stdout
I've got an error : No valid rules left

Any idea ? I use the last version 6.2.5
Thanks for reading and help me please.