Delete the existing keystore, under /etc
Using the info contained in its README, re-create it (in interactive mode), for example with a 2 year (365 * 2) days of validity:
keytool -genkeypair -keystore pivot.keystore -validity 730 -alias pivot
and give to it the following data (only values, without field keys)
CN=Apache Pivot, OU=Apache Pivot, O=Apache Software Foundation, ... C=US
keytool -list -v -keystore keystore.jks -alias pivot
Try to do a full build of Pivot sources and binary distribution, to ensure that all is good.