You may receive a warning about a possible scale error in two places. When Coded Target Presets are applied, a warning will come up if the maximum scale error is high, or during Export pre-check, if any active scale in the project has an error above a threshold the warning will appear to let you know your export may not be the correct size.
A large scale error is an indication of poor fit, and possible sources of error should be investigated. Check your target marking, monitor your Marking Residuals, and processing Final Total Error etc. and track down the sources of error.
Sometimes coded target projects with high deltas are due to miscoded target(s) (e.g. due to blur, glare, shadows, occlusions, or mirrors) where one or more point solutions is weak causing a discrepancy between the measured and calculated distance in the scale pair.
Additionally, it could be that the wrong Preset was applied, or in some cases a target pair that was cut up and no longer is the correct distance apart in the project.
You can also disable an individual scale if the other scales in the project are ok. Investigate by looking at the Check Distances Table. Look for a scale that has the highest error. Then open the Imports and Coordinate Systems Pane to disable the offending scale and recheck the Check Distances table to see if all errors are small (usually under 5%). Repeat until corrected. Note if several scales have high error and disabling the large ones does not fix it, there may be other issues (such as the wrong preset, poor camera calibration, or poor orientation).