Temporary fix without enabling feedback to Mozilla.
Open the address about:config in the Tor Browser address bar At the top of the page, search for xpinstall.signatures.required Set the xpinstall.signatures.requiredentry to false by double clicking it
Note: This workaround should only be used temporarily, as it disables a security feature. Please remember to set the xpinstall.signatures.requiredentry back to true again once the Tor Browser security update is applied.