ERROR: Sequence contains more than one matching element

Questions
1

After upgrading from 7.3.4 to Umbraco 7.3.8, I am now getting an error on particular nodes:

Failed to retrieve data for content id 5314

Sequence contains more than one matching element

EXCEPTION DETAILS:

System.InvalidOperationException: Sequence contains more than one matching element
STACKTRACE:

at System.Linq.Enumerable.SingleOrDefault[TSource](IEnumerable`1 source, Func`2 predicate)
   at Umbraco.Core.Persistence.Repositories.VersionableRepositoryBase`2.GetPropertyCollection(Sql docSql, IEnumerable`1 documentDefs)
   at Umbraco.Core.Persistence.Repositories.ContentRepository.CreateContentFromDto(DocumentDto dto, Guid versionId, Sql docSql)
   at Umbraco.Core.Persistence.Repositories.ContentRepository.PerformGet(Int32 id)
   at Umbraco.Core.Cache.DefaultRepositoryCachePolicy`2.Get(TId id, Func`2 getFromRepo)
   at Umbraco.Core.Persistence.Repositories.RepositoryBase`2.Get(TId id)
   at Umbraco.Core.Services.ContentService.GetById(Int32 id)
   at Umbraco.Web.Editors.ContentController.CheckPermissions(IDictionary`2

Any ideas how this can be fixed?

This is a companion discussion topic for the original entry at https://our.umbraco.com/forum/78370-error-sequence-contains-more-than-one-matching-element