The following Microsoft Office solution cannot be installed due to a general installer error: SlideLizard.vsto 0x8007007E

This error happens when your computer is missing a specific Microsoft software package which enables the installation of Microsoft Office Add-Ons.


  1. Download & install the required software from Microsoft:  Download Visual Studio 2010 Tools for Office Runtime from Official Microsoft Download Center (this may require Administrator privileges).
  2. Restart the installation of SlideLizard.

Your security settings do not allow this application to be installed on your computer

Your administrator has blocked this application because it potentially poses a security risk to your computer.

This error can occur if your security settings are different than the Windows standard settings (and therefore do not allow the installation of so-called ClickOnce applications).


  1. Download and run (double click) the following fileFix installation not allowed.

    This will adjust your settings to allow the installation. You can find more information here: Microsoft documentation – ClickOnce Prompt Behaviour.

Manifest not valid / Invalid Deployment Exception

System.Deployment.Application.InvalidDeploymentException: Exception reading manifest from file:///C:/Users/XXX/AppData/Roaming/SlideLizard/Installer/SlideLizard.PowerPointAddIn.vsto: the manifest may not be valid or the file could not be opened. ---> System.Deployment.Application.InvalidDeploymentException: Manifest XML signature is not valid. --> System.Security.Cryptography.CryptographicException: SignatureDescription could not be created for the signature algorithm supplied. at System.Security.Cryptography.Xml.SignedXml.CheckSignedInfo(AsymmetricAlgorithm key) at System.Security.Cryptography.Xml.SignedXml.CheckSignatureReturningKey(AsymmetricAlgorithm& signingKey) at System.Deployment.Internal.CodeSigning.SignedCmiManifest.Verify(CmiManifestVerifyFlags verifyFlags) at System.Deployment.Application.Manifest.AssemblyManifest.ValidateSignature(Streams)

If you get a similar error to this, you need to allow the installation of ClickOnce applications(for more information check out


  1. Open the registry editor:
    1. Click Start, and then click Run.
    2. In the Open box, type regedit, and then click OK.
  2. Find the following registry key: \HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\.NETFramework\Security\TrustManager\PromptingLevel . If the key does not exist, create it.
  3. Add the following subkey as String Value, if it doesn’t already exist, or otherwise set it to this value:Internet Enabled
  4. Repeat step 3 also for this registry key:
  5. Try the installation again