When attempting to apply Predictive Coding, you see that all, or a large amount of items are noted as "Skipped (No Keywords Match) Document Count".
Cluster Analysis is the function that denotes the Keywords. Ensure that the "ClusterID" column is populated for all items within your project.
If not all items have an assigned "ClusterID", meaning you have (Blank) items, then re-run Cluster Analysis until this column is fully populated. Depending on how large your project is, you may need to run Cluster Analysis multiple times.
Once all items have a ClusterID, run predictive coding again.
Cluster Analysis was not a chosen processing option, or it failed to fully populate the ClusterID information during initial processing.