topic Re: Custom Rendering Extension in Power BI Report Server in Report Server

Custom Rendering Extension in Power BI Report Server

Vishal-Sepaia_m — Mon, 28 Jul 2025 10:36:29 GMT

1. 1. I am attempting to implement a custom rendering extension (TabDelimitedRenderer) in Power BI Report Server to support exporting reports in a tab-delimited format. However, I am encountering the following issue:
    
    Error Message:
    "You have attempted to use a rendering extension that is either not registered for this report server or it is not supported in this edition of Reporting Services (rsRenderingExtensionNotFound)."
    Steps Taken:
    I created a custom rendering extension in C# that implements the IExtension interface.
    I deployed the compiled DLL (TabDelimited.dll) to the following directory:
    C:\Program Files\Microsoft SQL Server Reporting Services\SSRS\ReportServer\bin
    I updated the RSReportServer.config file with the following <Extension> entry:
    <Extension Name="TabDelimited" Type="TabDelimitedRenderer, TabDelimited" />
    
    Restarted the Power BI Report Server service.
    Environment Details:
    Power BI Report Server Version 2022
    
    Developer Edition
    
    Windows OS
    
    Custom Extension Details:
    Class Name: TabDelimitedRenderer
    Assembly Name: TabDelimited
    
    Questions:
    
    Does Power BI Report Server support custom rendering extensions like SQL Server Reporting Services (SSRS)?
    If supported, are there any additional steps required to enable the custom rendering extension?
    Are there any limitations or restrictions in specific editions of Power BI Report Server that could cause this issue?
    Could you provide guidance on resolving the rsRenderingExtensionNotFound error?
    Code snippet ::
    
    public class TabDelimitedRenderer : IExtension
    {
    public string LocalizedName => "Tab-Delimited";
    public bool Render(
    Stream reportStream,
    NameValueCollection reportParameters,
    NameValueCollection deviceInfo,
    NameValueCollection clientCapabilities,
    out string mimeType,
    out string fileExtension,
    out Encoding encoding,
    out Stream outputStream)
    {
    mimeType = "text/plain";
    fileExtension = "txt";
    encoding = Encoding.UTF8;
    outputStream = new MemoryStream();
    try
    {
    using (StreamReader reader = new StreamReader(reportStream, encoding))
    using (StreamWriter writer = new StreamWriter(outputStream, encoding, 1024, leaveOpen: true))
    {
    string line;
    while ((line = reader.ReadLine()) != null)
    {
    string[] columns = line.Split(',');
    writer.WriteLine(string.Join("\t", columns));
    }
    writer.Flush();
    }
    outputStream.Seek(0, SeekOrigin.Begin);
    }
    catch (Exception ex)
    {
    throw new ReportRenderingException("Error rendering Tab-Delimited format", ex);
    }
    return true;
    }
    public void SetConfiguration(string configuration) { }
    public void GetRenderingResource(string resourceName, Stream resourceStream, out string mimeType)
    {
    mimeType = null;
    }

Re: Custom Rendering Extension in Power BI Report Server

jaineshp — Mon, 28 Jul 2025 10:43:13 GMT

Power BI Report Server does not support custom rendering extensions like SQL Server Reporting Services (SSRS) does. This limitation causes the rsRenderingExtensionNotFound error when trying to register custom exporters.

To work around this:

Use the built-in export formats (CSV, Excel, etc.).
Perform any custom formatting (e.g., converting CSV to tab-delimited) externally with scripts or tools.
For full custom rendering extension support, consider using SSRS instead.

Modifying RSReportServer.config and deploying custom DLLs works in SSRS but is unsupported in Power BI Report Server 2022.

If this helped you, kindly give me kudos and mark my reply as the solution. Thanks!

Best regards,
Jainesh Poojara

Re: Custom Rendering Extension in Power BI Report Server

Vishal-Sepaia_m — Tue, 29 Jul 2025 04:21:02 GMT

Hi @jaineshp,

I am trying to do this in power bi report builder and i am using SSRS (i think):: saving my dll here (C:\Program Files\Microsoft SQL Server Reporting Services\SSRS\ReportServer\bin)

isnt it the same thing?

I am pretty new to power bi.

Thanks

Re: Custom Rendering Extension in Power BI Report Server

jaineshp — Tue, 29 Jul 2025 10:52:11 GMT

Hi @Vishal-Sepaia_m ,

Power BI Report Server does not support custom rendering extensions, unlike SQL Server Reporting Services (SSRS). This limitation is the reason behind the following error:

rsRenderingExtensionNotFound: You have attempted to use a rendering extension that is either not registered for this report server or it is not supported in this edition of Reporting Services.

Workaround Options:

Use the built-in export formats (e.g., CSV, Excel, PDF).
Perform any required custom formatting (such as converting CSV to tab-delimited) externally using PowerShell, C#, or other tools.
If custom rendering extensions are essential to your use case, consider hosting your .rdl reports in SQL Server Reporting Services (SSRS) 2019 or 2022, which does support custom rendering extensions.

Note: While modifying RSReportServer.config and deploying custom DLLs works in SSRS, it is not supported in Power BI Report Server 2022, even though the folder structure and configuration files appear similar.

Re: Custom Rendering Extension in Power BI Report Server

v-hashadapu — Mon, 04 Aug 2025 11:11:59 GMT

Hi @Vishal-Sepaia_m , hope you are doing great. May we know if your issue is solved or if you are still experiencing difficulties. Please share the details as it will help the community, especially others with similar issues.

Re: Custom Rendering Extension in Power BI Report Server

v-hashadapu — Thu, 07 Aug 2025 12:30:28 GMT

Hi @Vishal-Sepaia_m , Hope you're doing okay! May we know if it worked for you, or are you still experiencing difficulties? Let us know — your feedback can really help others in the same situation.