I have a custom field,
1.field name: notifyList
2.field type:Table Grid Editor.
3.field configuration:
gd.columns=isummary,iassignee,istatus,idue
gd.tablename=actions
gd.ds=jira
col.isummary=Summary
col.isummary.name=summary
col.isummary.type=string
col.isummary.required=true
col.isummary.maxLength=128
col.isummary.width=400
col.iassignee=Assignee
col.iassignee.type=userlist
col.iassignee.formatUser={username}
col.iassignee.required=true
col.iassignee.allow.roles=Users
col.iassignee.autocomplete=true
col.iassignee.width=100
col.istatus=Status
col.istatus.type=list
col.istatus.list.size=2
col.istatus.name1=Open
col.istatus.value1=O
col.istatus.name2=Done
col.istatus.value2=D
col.istatus.width=60
col.istatus.defaultValue=O
col.idue=Date due
col.idue.type=date
col.idue.defaultDate = +1w
4. I select a user "wangsheng" in for field Assignee

5. when moving the focus to other field, the assignee show blank.

6. when moving focus to Assignee back, the field shows value "wangsheng" again.
7. the log is, there is a NullPointerException.
2022-03-23 16:00:21,118 Caesium-1-1 INFO ServiceRunner [c.a.crowd.directory.DbCachingRemoteChangeOperations] scanned and compared [ 81 ] groups for update in DB cache in [ 8ms ]
2022-03-23 16:00:21,132 Caesium-1-1 INFO ServiceRunner [c.a.crowd.directory.DbCachingRemoteChangeOperations] updated [ 3 ] groups successfully in [ 14ms ]
2022-03-23 16:00:21,132 Caesium-1-1 INFO ServiceRunner [c.a.crowd.directory.DirectoryCacheImplUsingChangeOperations] synchronized [ 81 ] groups in [ 22ms ]
2022-03-23 16:00:21,240 Caesium-1-1 INFO ServiceRunner [c.a.c.d.ldap.cache.AbstractCacheRefresher] finished group attribute sync with 0 failures in [ 108ms ]
2022-03-23 16:00:25,034 Caesium-1-1 INFO ServiceRunner [c.a.crowd.directory.DbCachingRemoteDirectory] FULL synchronisation complete for directory [ 10000 ] in [ 5705ms ]
2022-03-23 16:01:02,768 http-nio-8080-exec-4 ERROR zhangliansheng 961x9191x1 1n906x3 223.111.8.125 /rest/idalko-igrid/1.0/datagrid/formatUser [c.a.p.r.c.error.jersey.ThrowableExceptionMapper] Uncaught exception thrown by REST service: null
java.lang.NullPointerException
at com.idalko.jira.plugins.igrid.rest.GridResource.doFormatUser(GridResource.java:1157)
at sun.reflect.GeneratedMethodAccessor1862.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at com.atlassian.plugins.rest.common.interceptor.impl.DispatchProviderHelper$ResponseOutInvoker$1.invoke(DispatchProviderHelper.java:192)
... 18 filtered
at com.atlassian.plugins.rest.module.RestDelegatingServletFilter$JerseyOsgiServletContainer.doFilter(RestDelegatingServletFilter.java:154)
... 1 filtered
at com.atlassian.plugins.rest.module.RestDelegatingServletFilter.doFilter(RestDelegatingServletFilter.java:68)
... 41 filtered
at com.atlassian.web.servlet.plugin.request.RedirectInterceptingFilter.doFilter(RedirectInterceptingFilter.java:21)
... 53 filtered
at com.atlassian.jira.security.JiraSecurityFilter.lambda$doFilter$0(JiraSecurityFilter.java:66)
... 1 filtered
at com.atlassian.jira.security.JiraSecurityFilter.doFilter(JiraSecurityFilter.java:64)
... 16 filtered
at com.atlassian.plugins.rest.module.servlet.RestSeraphFilter.doFilter(RestSeraphFilter.java:37)
... 19 filtered
at com.atlassian.jira.servermetrics.CorrelationIdPopulatorFilter.doFilter(CorrelationIdPopulatorFilter.java:30)
... 5 filtered
at com.idalko.tgng.jira.server.models.servicedesk.ServletRequestContextFilter.$anonfun$doFilter$1(ServletRequestContextFilter.scala:13)
at scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:12)
at scala.util.Try$.apply(Try.scala:209)
at com.idalko.tgng.jira.server.models.servicedesk.ServletRequestContextFilter.doFilter(ServletRequestContextFilter.scala:13)
... 3 filtered
at com.idalko.jira.plugins.igrid.servicedesk.ServletRequestContextFilter.doFilter(ServletRequestContextFilter.java:23)
... 8 filtered
at com.atlassian.web.servlet.plugin.request.RedirectInterceptingFilter.doFilter(RedirectInterceptingFilter.java:21)
... 4 filtered
at com.atlassian.web.servlet.plugin.LocationCleanerFilter.doFilter(LocationCleanerFilter.java:36)
... 7 filtered
at net.bull.javamelody.MonitoringFilter.doFilter(MonitoringFilter.java:239)
at net.bull.javamelody.MonitoringFilter.doFilter(MonitoringFilter.java:215)
at net.bull.javamelody.PluginMonitoringFilter.doFilter(PluginMonitoringFilter.java:88)
at net.bull.javamelody.JiraMonitoringFilter.doFilter(JiraMonitoringFilter.java:137)
... 22 filtered
at com.atlassian.jira.servermetrics.MetricsCollectorFilter.doFilter(MetricsCollectorFilter.java:25)
... 23 filtered
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
2022-03-23 16:01:02,864 http-nio-8080-exec-11 ERROR zhangliansheng 961x9193x1 1n906x3 223.111.8.125 /rest/idalko-igrid/1.0/datagrid/formatUser [c.a.p.r.c.error.jersey.ThrowableExceptionMapper] Uncaught exception thrown by REST service: null
java.lang.NullPointerException
at com.idalko.jira.plugins.igrid.rest.GridResource.doFormatUser(GridResource.java:1157)
at sun.reflect.GeneratedMethodAccessor1862.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at com.atlassian.plugins.rest.common.interceptor.impl.DispatchProviderHelper$ResponseOutInvoker$1.invoke(DispatchProviderHelper.java:192)
... 18 filtered
at com.atlassian.plugins.rest.module.RestDelegatingServletFilter$JerseyOsgiServletContainer.doFilter(RestDelegatingServletFilter.java:154)
... 1 filtered
at com.atlassian.plugins.rest.module.RestDelegatingServletFilter.doFilter(RestDelegatingServletFilter.java:68)
... 41 filtered
at com.atlassian.web.servlet.plugin.request.RedirectInterceptingFilter.doFilter(RedirectInterceptingFilter.java:21)
... 53 filtered
at com.atlassian.jira.security.JiraSecurityFilter.lambda$doFilter$0(JiraSecurityFilter.java:66)
... 1 filtered
at com.atlassian.jira.security.JiraSecurityFilter.doFilter(JiraSecurityFilter.java:64)
... 16 filtered
at com.atlassian.plugins.rest.module.servlet.RestSeraphFilter.doFilter(RestSeraphFilter.java:37)
... 19 filtered
at com.atlassian.jira.servermetrics.CorrelationIdPopulatorFilter.doFilter(CorrelationIdPopulatorFilter.java:30)
... 5 filtered
at com.idalko.tgng.jira.server.models.servicedesk.ServletRequestContextFilter.$anonfun$doFilter$1(ServletRequestContextFilter.scala:13)
at scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:12)
at scala.util.Try$.apply(Try.scala:209)
at com.idalko.tgng.jira.server.models.servicedesk.ServletRequestContextFilter.doFilter(ServletRequestContextFilter.scala:13)
... 3 filtered
at com.idalko.jira.plugins.igrid.servicedesk.ServletRequestContextFilter.doFilter(ServletRequestContextFilter.java:23)
... 8 filtered
at com.atlassian.web.servlet.plugin.request.RedirectInterceptingFilter.doFilter(RedirectInterceptingFilter.java:21)
... 4 filtered
at com.atlassian.web.servlet.plugin.LocationCleanerFilter.doFilter(LocationCleanerFilter.java:36)
... 7 filtered
at net.bull.javamelody.MonitoringFilter.doFilter(MonitoringFilter.java:239)
at net.bull.javamelody.MonitoringFilter.doFilter(MonitoringFilter.java:215)
at net.bull.javamelody.PluginMonitoringFilter.doFilter(PluginMonitoringFilter.java:88)
at net.bull.javamelody.JiraMonitoringFilter.doFilter(JiraMonitoringFilter.java:137)
... 22 filtered
at com.atlassian.jira.servermetrics.MetricsCollectorFilter.doFilter(MetricsCollectorFilter.java:25)
... 23 filtered
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
2022-03-23 16:01:19,331 Caesium-1-1 INFO ServiceRunner [c.a.crowd.directory.DbCachingRemoteDirectory] INCREMENTAL synchronisation for directory [ 10000 ] starting
2022-03-23 16:01:19,331 Caesium-1-1 INFO ServiceRunner [c.a.crowd.directory.DbCachingRemoteDirectory] Attempting INCREMENTAL synchronisation for directory [ 10000 ]
8. jira version: 7.6.1
9. iDalko Table Grid plugin version 1.29.17
Is there any solution to resolve it or walk around?