Unrecognized tag in cc config.xml
From BOINC Wiki
This is an error you will see when you run a new BOINC client 7.0 or above but still have code specifically for BOINC 5 and 6 in your core client configuration file cc_config.xml.
Example give: Unrecognized tag in cc_config.xml: <zero_debts>
The BOINC 7 client doesn't use these debts anymore, so zeroing those debts isn't going to work, the <zero_debts> tag has been deprecated.