Error importing products

I'm getting an "The event manager has been stopped." error after about 15 minutes of running an import job.

System.AggregateException
  HResult=0x80131500
  Message=One or more errors occurred.
  Source=Mediachase.DataProvider
  StackTrace:
   at Mediachase.Data.Provider.TransactionScope.ExecuteActions(IEnumerable`1 actions)
   at Mediachase.Data.Provider.TransactionScope.ThreadStaticTransactionScope.Commit()
   at Mediachase.Data.Provider.TransactionScope.Complete()
   at EPiServer.Commerce.Catalog.Provider.CatalogContentCommitterHandler.SaveVersionInternal(CatalogContentBase content, SaveAction action, String currentUser)
   at EPiServer.Commerce.Catalog.Provider.CatalogContentCommitterHandler.Save(CatalogContentBase content, SaveAction action, String currentUser)
   at EPiServer.Commerce.Catalog.Provider.CatalogContentProvider.Save(IContent content, SaveAction action)
   at EPiServer.Core.Internal.DefaultContentRepository.Save(IContent content, SaveAction action, AccessLevel access)
   at ETL.ProductImporter.ProductImporter.<>c__DisplayClass68_1.<UpsertCustomProduct>b__0() in C:\Projects\ETL\ProductImporter\ProductImporter.cs:line 887
Inner Exception 1:
InvalidOperationException: The event manager has been stopped.

Anyway to avoid this error? It's running from inside a Hangfire task instead of a scheduledJob.

error is throw when i call this code:

return contentRepo.Save(productToChange, SaveAction.Publish, AccessLevel.NoAccess);