Protocol error (Error): Extension is invalid from: server0.conn0.webExtensionDescriptor65 (resource://gre/modules/addons/XPIInstall.jsm:463:17)

Error

Protocol error (Error): Extension is invalid from: server0.conn0.webExtensionDescriptor65 (resource://gre/modules/addons/XPIInstall.jsm:463:17)  

Got this error message. I:

  1. copy+pasted an existing webextension into a new folder & loaded it into firefox.
  2. Modified the manifest
  3. Reduced the 'manifest version' to 1
    • Post-solution, it told me that 1 is too small. So maybe it has to be 2 or greater as a rule??
    • The manifest version actually HAS to be 2. I thought this was my versioning, but it's not, I guess.
  4. Got this error.

Solution

  • Remove the add-on and re-add it
  • or increment your manifest version.