RuleSet is not accepting valid rules

[spartida-iteso]

I have this rule in my xml:

<description>
     Rules
</description>


<!-- Your rules will come here -->
<rule ref="category/plsql/design.xml/ExcessiveMethodLength">

But mentions with a pop up of this one is no valid.

I'm using the latest intellij version:
IntelliJ IDEA 2020.3.1 (Ultimate Edition)
Build #IU-203.6682.168, built on December 29, 2020
Licensed to IntelliJ IDEA Evaluator
Expiration date: February 10, 2021
Runtime version: 11.0.9.1+11-b1145.63 amd64
VM: OpenJDK 64-Bit Server VM by JetBrains s.r.o.
Windows 10 10.0
GC: ParNew, ConcurrentMarkSweep
Memory: 1992M
Cores: 4
Non-Bundled Plugins: PMDPlugin, IntelliJDeodorant, QAPlug, QAPlug - PMD, Pythonid, com.jetbrains.edu

Error: