structuredAttrs is enabled

trying https://addons.mozilla.org/firefox/downloads/file/4982740/tree_style_tab-4.4.0.xpi
  % Total    % Received % Xferd  Average Speed  Time    Time    Time   Current
                                 Dload  Upload  Total   Spent   Left   Speed

  0      0   0      0   0      0      0      0                              0
curl: (22) The requested URL returned error: 404
Warning: Problem (retrying all errors). Retrying in 1 second. 3 retries left.

  0      0   0      0   0      0      0      0                              0
curl: (22) The requested URL returned error: 404
Warning: Problem (retrying all errors). Retrying in 2 seconds. 2 retries left.

  0      0   0      0   0      0      0      0                              0
curl: (22) The requested URL returned error: 404
Warning: Problem (retrying all errors). Retrying in 4 seconds. 1 retry left.

  0      0   0      0   0      0      0      0                              0
curl: (22) The requested URL returned error: 404
error: cannot download tree_style_tab-4.4.0.xpi from any mirror