diff --git a/knowledge-base/images/DeveloperCommandPrompt.png b/knowledge-base/images/DeveloperCommandPrompt.png new file mode 100644 index 000000000..d461f2867 Binary files /dev/null and b/knowledge-base/images/DeveloperCommandPrompt.png differ diff --git a/knowledge-base/images/TelerikReportDesignerFolder.png b/knowledge-base/images/TelerikReportDesignerFolder.png new file mode 100644 index 000000000..158825a8a Binary files /dev/null and b/knowledge-base/images/TelerikReportDesignerFolder.png differ diff --git a/knowledge-base/resolving-microsoft-mshtml-assembly-error-telerik-report-designer.md b/knowledge-base/resolving-microsoft-mshtml-assembly-error-telerik-report-designer.md new file mode 100644 index 000000000..c13b986e6 --- /dev/null +++ b/knowledge-base/resolving-microsoft-mshtml-assembly-error-telerik-report-designer.md @@ -0,0 +1,78 @@ +--- +title: Fixing "Could not load file or assembly Microsoft.mshtml" Error +description: Resolve the "Could not load file or assembly Microsoft.mshtml" error encountered in Telerik Report Designer when designing reports. +type: how-to +page_title: Resolving Microsoft.mshtml Assembly Error in Telerik Report Designer +meta_title: Resolving Microsoft.mshtml Assembly Error in Telerik Report Designer +slug: resolving-microsoft-mshtml-assembly-error-telerik-report-designer +tags: telerik reporting, error handling, microsoft.mshtml, gac, assembly references +res_type: kb +ticketid: 1692750 +--- + +## Environment + + + + + + + + +
ProductProgress® Telerik® Reporting
+ +## Description + +I encounter the `Could not load file or assembly Microsoft.mshtml` error when working with Telerik Report Designer. This happens consistently while updating or designing reports, particularly when adding a subreport and using an [HTMLTextBox]({%slug telerikreporting/designing-reports/report-structure/htmltextbox/overview%}) for a different SQL query. The error forces the system to shut down, requiring a restart. + +## Solution + +To resolve the "Could not load file or assembly Microsoft.mshtml" error, follow these steps: + +### Step 1: Copy the Assembly to the Designer Folder + +1. Locate the `microsoft.mshtml.dll` assembly file on your system. +1. Copy the file to the Telerik Report Designer folder. + + ![Telerik Report Designer folder](images/TelerikReportDesignerFolder.png) + +1. Open the report file (for example, `SampleReport.trdp`) and select the HTMLTextBox to check if the error is resolved. + +### Step 2: Add Assembly Reference to the Configuration Files + +1. Open the `Telerik.ReportDesigner.exe.config` or `Telerik.ReportDesigner.x86.exe.config` file. +1. Add the following assembly reference. Ensure the `` section is properly registered: + + ````XML + + +
+ + // ... + + + + + + // ... +```` + + +1. Save the changes and relaunch Telerik Report Designer. + +### Step 3: Install Microsoft.mshtml in the Global Assembly Cache (GAC) + +1. Open the Developer Command Prompt for Visual Studio. + + ![Developer Command Prompt](images/DeveloperCommandPrompt.png) + +1. Run the command `gacutil /l microsoft.mshtml` to check if the assembly exists in the GAC. It should display `Number of items = 0` if missing. +1. Navigate to the directory containing the `microsoft.mshtml.dll` file. +1. Execute the following command to install the assembly: `gacutil /i microsoft.mshtml.dll`. +1. Verify installation with `gacutil /l microsoft.mshtml`. + +## See Also + +*[Global Assembly Cache (GAC)](https://learn.microsoft.com/en-us/dotnet/framework/app-domains/gac) +*[Install an assembly into the global assembly cache](https://learn.microsoft.com/en-us/dotnet/framework/app-domains/install-assembly-into-gac)