The analyzer identified a compatibility issue. Tool parameters have a multiValue property that is either True or False, and the identified parameter's multiValue property is not consistent at the current version and the selected target version.
Use the target version of the software to review the processes in model and script tools that were identified with compatibility issues. Review the version-appropriate tool documentation, run the model or script tool, and review the output to confirm it is acceptable.
See the Analyze Toolbox For Version tool documentation for more information.