Your error message says:
DB2 SQL Error: SQLCODE=-104, SQLSTATE=42601
-104 represents SQL0104N and here is explanation.
SQL0104N An unexpected token token was found following text. Expected tokens may include: token-list.
https://www.ibm.com/support/knowledgecenter/en/SSEPGG_11.5.0/com.ibm.db2.luw.messages.sql.doc/com.ibm.db2.luw.messages.sql.doc-gentopic1.html#sql0104n
Explanation
A syntax error in the SQL statement or the input command string for the SYSPROC.ADMIN_CMD procedure was detected at the specified token following the text text. The text field indicates the 20 characters of the SQL statement or the input command string for the SYSPROC.ADMIN_CMD procedure that preceded the token that is not valid.
As an aid, a partial list of valid tokens is provided in the SQLERRM field of the SQLCA as token-list. This list assumes the statement is correct to that point.
This message can be returned when text is passed to the command line processor (CLP) in command mode and the text contains special characters that are interpreted by the operating system shell, such as single or double quotes, which are not identified with an escape character.
The statement cannot be processed.
So you may need to follow "User response" section of the page and correct SQL statement in demo.sql.
Hope this helps.