Currently, whenever I try to award xp at the end of a session, the API crashes and I get this error: Error: Firebase.update failed: First argument contains NaN in property 'current' Error: Firebase.update failed: First argument contains NaN in property 'current' at Ba (/home/node/d20-api-server/node_modules/firebase/lib/firebase-node.js:9:186) at Ba (/home/node/d20-api-server/node_modules/firebase/lib/firebase-node.js:10:207) at Aa (/home/node/d20-api-server/node_modules/firebase/lib/firebase-node.js:8:462) at Ea (/home/node/d20-api-server/node_modules/firebase/lib/firebase-node.js:10:403) at J.update (/home/node/d20-api-server/node_modules/firebase/lib/firebase-node.js:146:318) at TrackedObj._doSave (/home/node/d20-api-server/api.js:850:27) at later (/home/node/d20-api-server/node_modules/underscore/underscore.js:892:31) at Timeout._onTimeout (/home/node/d20-api-server/node_modules/underscore/underscore.js:829:19) at ontimeout (timers.js:386:14) at tryOnTimeout (timers.js:250:5) Any help would be appreciated. Scripts used are these .