Sitecore Multisite - Unexpected provider type: System.String. Expected: Sitecore.Links.LinkProvider

Hi Team,

Today's blog post is regarding real live scenario which we came across while having multisite solution in Sitecore headless set up.

Well, We have had couple of deployments but one fine morning after the deployment we started getting below error on our stagging site (UAT)

and in Sitecore logs we were getting same following logs 

Exception: System.InvalidOperationException

Message: Unexpected provider type: System.String. Expected: Sitecore.Links.LinkProvider

Source: Sitecore.Kernel

   at Sitecore.Configuration.DefaultFactory.GetProviders[TProvider,TCollection](List`1 nodes)

   at Sitecore.Configuration.DefaultFactory.GetProviders[TProvider,TCollection](String rootPath, TProvider& defaultProvider)

   at Sitecore.Configuration.ProviderHelper`2.ReadProviders()

   at Sitecore.Configuration.ProviderHelper`2.get_Provider()

   at Sitecore.Links.DefaultLinkManager.ParseRequestUrl(HttpRequest request)

   at Sitecore.Web.RequestUrl.Parse(HttpRequestBase request)

   at Sitecore.Pipelines.HttpRequest.HttpRequestArgs.Initialize()

   at Sitecore.Pipelines.CorePipeline.Run(PipelineArgs args)

   at Sitecore.Pipelines.DefaultCorePipelineManager.Run(String pipelineName, PipelineArgs args, String pipelineDomain, Boolean failIfNotExists)

   at Sitecore.Pipelines.DefaultCorePipelineManager.Run(String pipelineName, PipelineArgs args, String pipelineDomain)

   at Sitecore.Web.RequestEventsHandler.OnBeginRequest(HttpContextBase context)

   at Sitecore.Nexus.Web.HttpModule.HttpApplication_BeginRequest(Object sender, EventArgs e)

   at System.Web.HttpApplication.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()

   at System.Web.HttpApplication.ExecuteStepImpl(IExecutionStep step)

   at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

Troubleshooting & Solution

Our actual set up is, We have

1) One site with headless SXA 

2) One legacy headless site without SXA

and development of both happening in parallel with two different team but deployments are planned in such a way that non SXA site gets deployed first and then the other SXA site on different times.

Now, Above error clearly says that on UAT, it is not able to find the LinkProvider which is configured, and previously it was working, So following was the patch which was applied and went on to both DEV and UAT server, but on DEV it worked fine and on UAT it is failing

<?xml version="1.0" encoding="utf-8"?>

<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/">

  <sitecore>

    <linkManager>

      <providers>

        <add name="localizedProvider">

          <patch:attribute name="lowercaseUrls">true</patch:attribute>

        </add>

      </providers>

    </linkManager>

    <links>

      <urlBuilder>

        <lowercaseUrls>true</lowercaseUrls>

      </urlBuilder>

    </links>

  </sitecore>

</configuration>

Thanks to my colleague Ajay Gour who reviewed past commits and we figured the patch which went up.

So we looked at the showconfig.aspx of working DEV environment and compared it with above patch and found our that patch is looking for "localizedProvider" which requires SXA to be installed otherwise it will never find that provider and above yellow screen will come and because on DEV both the team are working SXA was installed and hence that patch was working.

Basically, Because of having same Sitecore instance for both the SXA and non SXA site, this patch went up but for this patch to work prerequisites is, SXA should have been installed for this "localizedProvider" to work

So solution to this was either to install SXA dependencies being same sitecore instance or changing the patch to target the default Sitecore link provider and patch it, Because for the site which is non SXA should not have dependencies on provider of SXA site

Because deployments for both sites can took place at different time expecting SXA to be present on Sitecore instance is not valid

so we changed that patch to following

<?xml version="1.0" encoding="utf-8"?>

<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/">

  <sitecore>

    <linkManager defaultProvider="sitecore">

      <providers>

        <add name="sitecore">

          <patch:attribute name="lowercaseUrls">true</patch:attribute>

        </add>

      </providers>

    </linkManager>

    <links>

      <urlBuilder>

        <lowercaseUrls>true</lowercaseUrls>

      </urlBuilder>

    </links>

  </sitecore>

</configuration>

 

Above patch we made sure that it does not target the localizedProvider because if SXA is not installed, it will not work & for the sites which needs SXA when they go live, we made sure that those sites have "localizedProvider" selected from site settings so it works for both the sites with different link provider. 

Installing SXA is also an option, and keep the patch same, but we did not want SXA dependencies for legacy sites though it will  be one time activity.

Now when the site with SXA will go live, we will revisit and check things for both of them and because SXA site has provider configured in its site setting it should work "as-is"

Thank you for my partner in all these troubleshooting and discussions Kiran Sawant my team member for his help and making sure that changes are propagated to environments and checked.