If you get this message you need to put the windows userid you are using to run BIDA into the the DB2USERS or DB2ADMINS windows user group and then you must also reboot the machine.
We found that when we started using the sql command processors against a DB2 server that was not installed using Administrator on the same machine, as we did in testing, that you needed to add the windows userid connecting to DB2 via ODBC in to these groups.
It’s a bit of a pain because there is no error message created and it took a while to find this blog post.
https://www.ibm.com/support/pages/sqlstate-im004-sqlallochandle-sqlhandleenv-failed-when-connecting-odbc-application
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