Some of the records in the dataset have invalid geometry or invalid attribute data (or both). Those records (up to the first 30 encountered) are listed. Records that cannot be read will not be included in the analysis.
Examine the corresponding fields selected for the analysis to identify NULL values. If the tool is spatial in nature, you should identify whether there are any invalid geometry values using the Check Geometry tool. Any invalid geometries can be repaired using the Repair Geometry tool.