Add-on policy

Add-ons Development
26

hi im trying to enable add-on access with policy:

<policy name="BlockAboutAddons" class="Both"
displayName="$(string.BlockAboutAddons)"  
explainText="$(string.BlockAboutAddons_Explain)" key="Software\Policies\Mozilla
\Firefox"
valueName="BlockAboutAddons">
  <parentCategory ref="firefox"/>
  <supportedOn ref="SUPPORTED_FF60"/>
  <enabledValue>
    <decimal value="1"/>
  </enabledValue>
  <disabledValue>
    <decimal value="0"/>
  </disabledValue>
</policy>

So in the windows registry i created & tried with those keys:

[HKEY_LOCAL_MACHINE\Software\Policies\Mozilla\Firefox] 
"BlockAboutAddons"="1"

[HKEY_LOCAL_MACHINE\Software\Mozzilla\Firefox] 
"BlockAboutAddons"="1"

[HKEY_CURRENT_USER\Software\Policies\Mozilla\Firefox] 
"BlockAboutAddons"="1"

[HKEY_CURRENT_USER\Software\Mozilla\Firefox] 
"BlockAboutAddons"="1"

but nothing works i still have access to about:addons