The length of the original exceeds maximum copy length.
If your Teriostar is 1020 model, maximum copy length is 2.5 m.
If your Teriostar is 1020L model, you can copy up to 10 m by setting "ScanMedia" to "HDD".
Refer to “Copying long original” in user’s guide.

Note: When HDD is selected in ScanMedia, print speed slows down to half. It is recommended to set ScanMedia to HDD only when you copy long originals.