If you see red highlighted fields in your click through and events spreadsheet during import validation,it means that:

Red highlighted fields in an import validation spreadsheet, particularly for click-throughs and events, consistently indicate errors that need correction. The "tool icon" typically refers to an interface element within the platform (like Amazon Ad Server) that provides details about these errors and often offers tools or suggestions for resolving them. Ignoring these highlighted fields will prevent successful import or lead to corrupted data. The import process has not stalled; rather, it has identified issues that require user intervention before it can proceed successfully.