Fix Upgrade Preview loading issues in ServiceNow Upgrade CenterIssue <!-- /*NS Branding Styles*/ --> .ns-kb-css-body-editor-container { p { font-size: 12pt; font-family: Lato; color: #000000; } span { font-size: 12pt; font-family: Lato; color: #000000; } h2 { font-size: 24pt; font-family: Lato; color: black; } h3 { font-size: 18pt; font-family: Lato; color: black; } h4 { font-size: 14pt; font-family: Lato; color: black; } a { font-size: 12pt; font-family: Lato; color: #00718F; } a:hover { font-size: 12pt; color: #024F69; } a:target { font-size: 12pt; color: #032D42; } a:visited { font-size: 12pt; color: #00718f; } ul { font-size: 12pt; font-family: Lato; } li { font-size: 12pt; font-family: Lato; } img { display: ; max-width: ; width: ; height: ; } } When the Upgrade Preview in ServiceNow Upgrade Center fails to load, displaying only a spinning wheel with no data and JavaScript errors related to undefined property values. The console displays a JavaScript error like the following: js_includes_upgrade_preview.jsx?v=03-03-2021_0818&lp=Mon_Apr_05_10_53_28_PDT_2021&c=32_1058:123 TypeError: Cannot read property 'value' of undefinedat getUpgradePreviewData (js_includes_upgrade_preview.jsx?v=03-03-2021_0818&lp=Mon_Apr_05_10_53_28_PDT_2021&c=32_1058:14330) In the localhost logs, you can see that it is failing when checking for Estimated Upgrade Completion Time: 2021-04-15 11:22:37 (342) Default-thread-13 8E743FD11BEBE450B3BC4223CD4BCB33 txid=42693f151beb SEVERE *** ERROR *** Failed to assemble response.java.lang.NullPointerException at com.glide.upgrade_center.UpgradeDurationResolver.checkSourceForEstimate(UpgradeDurationResolver.java:353) at com .glide.upgrade_center.UpgradeDurationResolver.checkAllSourcesForEstimate(UpgradeDurationResolver.java:400) at com.glide.upgrade_center.UpgradeDurationResolver.computeUpgradeDurationFromRemoteHistory(UpgradeDurationResolver.java:145) at com.glide.upgrade_center.UpgradeDurationResolver.<init>(UpgradeDurationResolver.java:133) at com.glide.upgrade_center.UpgradeDurationResolver.<init>(UpgradeDurationResolver.java:90) at com.glide.upgrade_center.preview.api.service.ServiceFacade.getScheduledUpgradeDurationEstimate(ServiceFacade.java:193) at com.glide.upgrade_center.preview.api.response.assembly.InstanceStateResponseAssembler.assemble(InstanceStateResponseAssembler.java:55) at com.glide.upgrade_center.preview.api.request.ARequestEndpoint.process(ARequestEndpoint.java:25) at com.glide.upgrade_center.preview.api.request.InstanceStateEndpoint.process(InstanceStateEndpoint.java:6) at com.glide.ui.ng.AngularProcessor.process0(AngularProcessor.java:233) at com.glide.ui.ng.AngularProcessor.process(AngularProcessor.java:178) at com.glide.processors.AProcessor.runProcessor(AProcessor.java:596) at com.glide.processors.AProcessor.processTransaction(AProcessor.java:266) at com.glide.processors.ProcessorRegistry.process0(ProcessorRegistry.java:181) at com.glide.processors.ProcessorRegistry.process(ProcessorRegistry.java:169) at com.glide.ui.GlideServletTransaction.process(GlideServletTransaction.java:44) at com.glide.sys.Transaction.run(Transaction.java:2275) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at java.lang.Thread.run(Thread.java:748) Release<!-- /*NS Branding Styles*/ --> .ns-kb-css-body-editor-container { p { font-size: 12pt; font-family: Lato; color: #000000; } span { font-size: 12pt; font-family: Lato; color: #000000; } h2 { font-size: 24pt; font-family: Lato; color: black; } h3 { font-size: 18pt; font-family: Lato; color: black; } h4 { font-size: 14pt; font-family: Lato; color: black; } a { font-size: 12pt; font-family: Lato; color: #00718F; } a:hover { font-size: 12pt; color: #024F69; } a:target { font-size: 12pt; color: #032D42; } a:visited { font-size: 12pt; color: #00718f; } ul { font-size: 12pt; font-family: Lato; } li { font-size: 12pt; font-family: Lato; } img { display: ; max-width: ; width: ; height: ; } } Beginning with Paris release Cause<!-- /*NS Branding Styles*/ --> .ns-kb-css-body-editor-container { p { font-size: 12pt; font-family: Lato; color: #000000; } span { font-size: 12pt; font-family: Lato; color: #000000; } h2 { font-size: 24pt; font-family: Lato; color: black; } h3 { font-size: 18pt; font-family: Lato; color: black; } h4 { font-size: 14pt; font-family: Lato; color: black; } a { font-size: 12pt; font-family: Lato; color: #00718F; } a:hover { font-size: 12pt; color: #024F69; } a:target { font-size: 12pt; color: #032D42; } a:visited { font-size: 12pt; color: #00718f; } ul { font-size: 12pt; font-family: Lato; } li { font-size: 12pt; font-family: Lato; } img { display: ; max-width: ; width: ; height: ; } } The Upgrade Engine fails because it cannot find valid external sources to determine the Upgrade Estimated Time. The engine checks for external sources in this order: The sys_property glide.upgrade.preview.duration.instance.id if it contains a valid remote instance sys_idAll instances in the Remote Instances [sys_update_set_source] table. Resolution<!-- /*NS Branding Styles*/ --> .ns-kb-css-body-editor-container { p { font-size: 12pt; font-family: Lato; color: #000000; } span { font-size: 12pt; font-family: Lato; color: #000000; } h2 { font-size: 24pt; font-family: Lato; color: black; } h3 { font-size: 18pt; font-family: Lato; color: black; } h4 { font-size: 14pt; font-family: Lato; color: black; } a { font-size: 12pt; font-family: Lato; color: #00718F; } a:hover { font-size: 12pt; color: #024F69; } a:target { font-size: 12pt; color: #032D42; } a:visited { font-size: 12pt; color: #00718f; } ul { font-size: 12pt; font-family: Lato; } li { font-size: 12pt; font-family: Lato; } img { display: ; max-width: ; width: ; height: ; } } Fix the issue using either of these methods: 1. Add a valid instance sys_id to the glide.upgrade.preview.duration.instance.id property. To find an instance id: Go to the sys_update_set_source table.Open a record.Right-select the header, and then select Show XML.Locate the instance_id value.Add this value to the property. 2. Verify all connections in the sys_update_set_source table. Select Test Connection on each record in the sys_update_set_source table. Related Links<!-- /*NS Branding Styles*/ --> .ns-kb-css-body-editor-container { p { font-size: 12pt; font-family: Lato; color: #000000; } span { font-size: 12pt; font-family: Lato; color: #000000; } h2 { font-size: 24pt; font-family: Lato; color: black; } h3 { font-size: 18pt; font-family: Lato; color: black; } h4 { font-size: 14pt; font-family: Lato; color: black; } a { font-size: 12pt; font-family: Lato; color: #00718F; } a:hover { font-size: 12pt; color: #024F69; } a:target { font-size: 12pt; color: #032D42; } a:visited { font-size: 12pt; color: #00718f; } ul { font-size: 12pt; font-family: Lato; } li { font-size: 12pt; font-family: Lato; } img { display: ; max-width: ; width: ; height: ; } } Upgrade Center properties