signing public key in command line not working

i keep getting this error message when attempting to sign my public key using the command line instruction:
```
Error in your post
-------------------

Code: 501
Name: DB_INSERT_ERROR
Description: failed to insert into database
```

Start by reproducing the command-line attempt to sign a public key and capture the full request context around the DB_INSERT_ERROR response. Done means the command completes without the reported database insertion error and the public key is signed.

Written by the indexing model from the issue text.