I had the same problem with SQL2008R2.

After some research I found out that the parameter -m 131 needs to be changed to -m 132 for SQL 2008R2 and after that change the length exception error disappeared!

Here is my final command line:

hashcat-cli64.exe -a 3 --pw-min=4 --pw-max=12 -m 132 -p : -o "SQL_passwords.txt" -n 7 hashes.txt -1 ?a ?1?1?1?1?1?1?1?1?1?1?1