Symptoms

Clover can't find valid decoders for a license key and fails with a given stack trace:

...
Execution default-cli of goal
com.atlassian.maven.plugins:clover-maven-plugin:4.1.1.:instrumentInternal
failed: Could not find any valid decoders in [clover.com.at
lassian.extras.decoder.v2.Version2LicenseDecoder@4fa7b2bf,clover.com
.atlassian.extras.decoder.v1.Version1LicenseDecoder@ac84274] for license
string at
...

Cause

A license key which was used has invalid format and could not be parsed by Clover.

Resolution

Most common mistakes are:

• copy-pasting only part of a license key
• not embedding a key in a CDATA section

• removing new line characters from a key (a license decoder is sensitive to this!), e.g.

  <!-- not correct -->
  <license><![CDATA[aaaaaabbbbbbccccccdddddd]]></license>
  
  <!-- correct -->
  <license><![CDATA[aaaaaa
  bbbbbb
  cccccc
  dddddd]]></license>

Check if your license key used is exactly the same as stated on my.atlassian.com.