This is a bug that pops up very occasionally, it’s due to a corrected Photoshop preference file. Go ahead and reset your PS preferences, restart Photoshop, and run the batch again. Let me know if that fixes the issue.

Note: Before resetting your preferences, make sure to save your current workspace (if customized) and to export and save any of your custom keyboard shortcuts and re-import them after. All of your plugins, plugin settings, and saved workspaces won’t be affected when resetting the preferences.