Sitecore 8.2 update 5 on Azure App Services. Anyone knows what could be the reason
<pipelines>
<indexing.getDependencies>
<processor type="Custom.Infrastructure.Pipelines.GetLocalDatasourceDependencies, Custom.Assembly" />
<!-- When indexing an item that is used as a datasource, make sure that all the items that reference the datasource in their presentation details gets re-indexed as well. -->
<processor type="Sitecore.ContentSearch.Pipelines.GetDependencies.GetDatasourceDependencies, Sitecore.ContentSearch"/>
</indexing.getDependencies>
</pipelines>
Error message:
Exception: System.NullReferenceException
Message: Object reference not set to an instance of an object.
Source: Sitecore.ContentSearch
at Sitecore.ContentSearch.Pipelines.GetDependencies.GetDatasourceDependencies.<>c.<GetSourceUris>b__1_0(ItemLink l)
at System.Linq.Enumerable.WhereSelectArrayIterator`2.MoveNext()
at System.Linq.Enumerable.WhereEnumerableIterator`1.MoveNext()
at System.Linq.Enumerable.<DistinctIterator>d__64`1.MoveNext()
at System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()
at System.Collections.Generic.List`1.InsertRange(Int32 index, IEnumerable`1 collection)
at Sitecore.ContentSearch.Pipelines.GetDependencies.GetDatasourceDependencies.Process(GetDependenciesArgs context)
at (Object , Object[] )
at Sitecore.Pipelines.CorePipeline.Run(PipelineArgs args)
at Sitecore.Pipelines.DefaultCorePipelineManager.Run(String pipelineName, PipelineArgs args, String pipelineDomain)
at Sitecore.Abstractions.CorePipelineWrapper.Run(String pipelineName, PipelineArgs args)
at Sitecore.ContentSearch.Pipelines.GetDependencies.GetDependenciesPipeline.GetIndexingDependencies(IIndexable indexable)
at Sitecore.ContentSearch.Crawler`1.UpdateDependents(IProviderUpdateContext context, T indexable)
at Sitecore.ContentSearch.SitecoreItemCrawler.DoUpdate(IProviderUpdateContext context, SitecoreIndexableItem indexable, IndexEntryOperationContext operationContext)
at Sitecore.ContentSearch.SitecoreItemCrawler.Update(IProviderUpdateContext context, IIndexableUniqueId indexableUniqueId, IndexEntryOperationContext operationContext, IndexingOptions indexingOptions)
at Sitecore.ContentSearch.AbstractSearchIndex.<>c__DisplayClass94_2.<PerformUpdate>b__0(IndexableInfo info, ParallelLoopState parallelLoopState)
at System.Threading.Tasks.Parallel.<>c__DisplayClass17_0`1.<ForWorker>b__1()
at System.Threading.Tasks.Task.InnerInvokeWithArg(Task childTask)
at System.Threading.Tasks.Task.<>c__DisplayClass176_0.<ExecuteSelfReplicating>b__0(Object <p0>)