ReportViewer control renders invalid HTML

Question

We have been using ReportViewer in our ASP.NET web forms site successfully for a long time (as in many years). We are in the process of upgrading to SQL Server 2022 and thought we'd get the latest ReportViewer control as well. Unfortunately, when we drop this in (using nuget), the report that gets rendered displays broken image icons. Using devtools, we can inspect one of the broken images and look at its markup. The image tag is invalid HTML. It appears to be messing up where to put the blank.gif property and ALT attribute. This was reported 3 years ago, but still seems to be an issue. There are work arounds (adding some custom CSS to the hosting aspx page), but why isn't this fixed in the reportviewer control itself?

<img 
src="/Reserved.ReportViewerWebControl.axd?ReportSession=rcy092c8e408e3.... blah.... blah...ResourceStreamID=Blank.gif ALT="  
blank="" 
image"="">

Originally asked in 2020:
https://learn.microsoft.com/en-us/answers/questions/190722/reportviewer-renders-invalid-html

Answer 1

Hi @Margo Noreen

You can submit a request at https://feedback.azure.com/forums/908035-sql-server.

If customers mention the request multiple times, the product team can consider adding this feature in the next version or making an update fix. Your feedback is valuable for us to improve our products and improve the level of service we provide.

Best regards,

Aniya