I had to roll back to 5.32, because I was still receiving errors after recreating the job. Here's one example --
Jan 17 14:36:31 ubuntu xo-server[19796]: 2019-01-17T20:36:31.133Z - xo:xapi - [DEBUG] exporting VDI xxxxxxx
Jan 17 14:36:31 ubuntu xo-server[19796]: 2019-01-17T20:36:31.349Z - xo:xo-server - [WARN] possibly unhandled rejection
Jan 17 14:36:31 ubuntu xo-server[19796]: { error:
Jan 17 14:36:31 ubuntu xo-server[19796]: { TypeError: Cannot read property 'join' of undefined
Jan 17 14:36:31 ubuntu xo-server[19796]: at new XapiError (/opt/xen-orchestra/packages/xen-api/src/index.js:92:28)
Jan 17 14:36:31 ubuntu xo-server[19796]: at wrapError (/opt/xen-orchestra/packages/xen-api/src/index.js:113:9)
Jan 17 14:36:31 ubuntu xo-server[19796]: at _call.catch.error (/opt/xen-orchestra/packages/xen-api/src/index.js:1129:18)
Jan 17 14:36:31 ubuntu xo-server[19796]: at tryCatcher (/opt/xen-orchestra/node_modules/bluebird/js/release/util.js:16:23)
Jan 17 14:36:31 ubuntu xo-server[19796]: at Promise._settlePromiseFromHandler (/opt/xen-orchestra/node_modules/bluebird/js/release/promise.js:512:31)
Jan 17 14:36:31 ubuntu xo-server[19796]: at Promise._settlePromise (/opt/xen-orchestra/node_modules/bluebird/js/release/promise.js:569:18)
Jan 17 14:36:31 ubuntu xo-server[19796]: at Promise._settlePromise0 (/opt/xen-orchestra/node_modules/bluebird/js/release/promise.js:614:10)
Jan 17 14:36:31 ubuntu xo-server[19796]: at Promise._settlePromises (/opt/xen-orchestra/node_modules/bluebird/js/release/promise.js:690:18)
Jan 17 14:36:31 ubuntu xo-server[19796]: at _drainQueueStep (/opt/xen-orchestra/node_modules/bluebird/js/release/async.js:138:12)
Jan 17 14:36:31 ubuntu xo-server[19796]: at _drainQueue (/opt/xen-orchestra/node_modules/bluebird/js/release/async.js:131:9)
Jan 17 14:36:31 ubuntu xo-server[19796]: at Async._drainQueues (/opt/xen-orchestra/node_modules/bluebird/js/release/async.js:147:5)
Jan 17 14:36:31 ubuntu xo-server[19796]: at Immediate.Async.drainQueues (/opt/xen-orchestra/node_modules/bluebird/js/release/async.js:17:14)
Jan 17 14:36:31 ubuntu xo-server[19796]: at runCallback (timers.js:810:20)
Jan 17 14:36:31 ubuntu xo-server[19796]: at tryOnImmediate (timers.js:768:5)
Jan 17 14:36:31 ubuntu xo-server[19796]: at processImmediate [as _immediateCallback] (timers.js:745:5)
Jan 17 14:36:31 ubuntu xo-server[19796]: [Symbol(originalCallSite)]:
Jan 17 14:36:31 ubuntu xo-server[19796]: [ CallSite {},
Jan 17 14:36:31 ubuntu xo-server[19796]: CallSite {},
Jan 17 14:36:31 ubuntu xo-server[19796]: CallSite {} ],
Jan 17 14:36:31 ubuntu xo-server[19796]: [Symbol(mutatedCallSite)]:
Jan 17 14:36:31 ubuntu xo-server[19796]: [ [Object],
Jan 17 14:36:31 ubuntu xo-server[19796]: [Object],
Jan 17 14:36:31 ubuntu xo-server[19796]: CallSite {},
Jan 17 14:36:31 ubuntu xo-server[19796]: CallSite {} ] } }
Retesting now with 5.32