We have an Umbraco 7.9 site on Windows Server 2008 R2.

We upgraded it from 7.5.8 two months ago. Now, on server reboot or occasionally on regularly scheduled app pool recycles, the Examine index doesn't return search results (on about 50% of the searches). This happens almost every week, during one of the IIS app pool recycles.

ERROR Umbraco.Web.PublishedCache.XmlPublishedCache.PublishedMediaCache - Could not load data from Examine index for media, the app domain is most likely in a shutdown state Lucene.Net.Store.AlreadyClosedException: this IndexReader is closed at Lucene.Net.Index.IndexReader.EnsureOpen() at Lucene.Net.Index.DirectoryReader.GetFieldNames(FieldOption fieldNames) at Examine.LuceneEngine.Providers.LuceneSearcher.GetSearchFields() in C:\projects\examine-qvx04\src\Examine\LuceneEngine\Providers\LuceneSearcher.cs:line 248 at UmbracoExamine.UmbracoExamineSearcher.GetSearchFields() at Examine.LuceneEngine.Providers.BaseLuceneSearcher.CreateSearchCriteria(String type, BooleanOperation defaultOperation) in C:\projects\examine-qvx04\src\Examine\LuceneEngine\Providers\BaseLuceneSearcher.cs:line 117 at UmbracoExamine.UmbracoExamineSearcher.CreateSearchCriteria(String type, BooleanOperation defaultOperation) at Umbraco.Web.PublishedCache.XmlPublishedCache.PublishedMediaCache.GetUmbracoMediaCacheValues(Int32 id)