The protein might be unable to function if an error during transcription occurs.
During transcription, the mRNA is formed. If the error encountered in the transcription, mRNA formed would be a transient one and would eventually get degraded. Also, during the translation process, the disruption would occur due to incorrect coding sequences and hence the functional protein will not be formed. The resulting protein will get degraded. Such proteins are termed as erroneous proteins.
they would not be able to function
Transcription is important to genetic information. If there is an error during the transcription process, the DNA copies would not be accurate, causing the proteins to be improperly assembled, or not assembled at all.
the protein would be made of the wrong amino acids