Data governance issues are grouped into several categories: data quality, data classification, data ownership, data access control, data privacy compliance, data retention and purging, data audit and monitoring, data documentation, data governance training, and overall data governance key performance and risk indicators. Common issues include inaccurate or missing data, unclassified or misclassified data, undefined data owners, unauthorized data access, non-compliance with privacy laws and policies, data retained past retention periods, infrequent audits, incomplete documentation, and lack of training and policy awareness.