The error might occur while viewing the Experience Analytics reports. The instance might fail to load a report data in the Dashboard if the amount of interactions with different pages is high. The Content Management (CM) server tries to load the data and fails because there is too much data to load. The following error can be found in the logs records:
1852 15:07:29 ERROR [Experience Analytics]: The query processor ran out of internal resources and could not produce a query plan. This is a rare event and only expected for extremely complex queries or queries that reference a very large number of tables or partitions. Please simplify the query. If you believe you have received this message in error, contact Customer Support Services for more information.
1852 15:07:29 ERROR [Experience Analytics]: System.Collections.Generic.KeyNotFoundException: The given key was not present in the dictionary.
at System.ThrowHelper.ThrowKeyNotFoundException()
at System.Collections.Generic.Dictionary`2.get_Item(TKey key)
at Sitecore.ExperienceAnalytics.Api.ReportDataService.ResolveDimensionKeys(List`1 reportRows, IReader`2 keysReader)
at Sitecore.ExperienceAnalytics.Api.ReportDataService.ExecuteQuery(IReportQueryData queryData, CachingPolicy cachingPolicy)
at Sitecore.ExperienceAnalytics.Api.ReportingService.RunQuery(ReportQuery reportQuery)
at Sitecore.ExperienceAnalytics.Api.Http.AnalyticsDataController.Get(ReportQuery reportQuery)
To resolve the issue, consider the following options:
Alternatively, you can use a lower value for the Experience Analytics default date range offset:
<setting name="ExperienceAnalytics.DefaultDateRangeOffset.From" value="-90" />
To do this, patch the value of the ExperienceAnalytics.DefaultDateRangeOffset.From found in the \App_Config\Sitecore\ExperienceAnalytics\Sitecore.ExperienceAnalytics.Client.config file with "-30" by creating a configuration patch file under the \App_Config\Include\zzz folder.