Odoo 14 sequence not working when create model (TypeError: not enough arguments for format string)

I have tried to follow tutorial odoo14, and it explain about sequence, I have followed the tutorial but sequence not working with error : TypeError: not enough arguments for format string.

After checking i realize that the mistake was in the prefix format in xml file.

it should be something like this : TC/%(year)s/%(month)s/ but i made it like this : TC/%(year)s/%(month)s%/

So i fix the xml file and restart the odoo server, but it still got the same problem, even i tried to search it from google, i still cannot find the error :(, until i check into the databases it self through setting-technical-sequence I can see that there were two same sequence but the first was the error one, so after i deleted it, everything run smoothly :).