CQM837E Dataset name including user prefix exceeds 44 characters. To avoid prefix, enclose DSN in single quotes.

Explanation
 The data set name specified already existed and
you specified N or PF3 as the response to the Replace
(Y/N) query. The file is not replaced.

User response
 Specify a new DSN or hit PF3 to exit the Export
CQM ISPF Log panel.