Web clipper stalling Safari

[AJ16S 0]

I decided to try to get more out of Evernote a weeks ago and installed the web clipper on Safari (10.0.3 on El Capitan).  Not really used it that much and didn't have any problems when I did.  The thing I did notice over the last few weeks was Safari stalling frequently when loading pages.  Typically the progress bar would get to around 20% and then the beachball would appear for around 20 seconds.  More prevalent on sites with a lot of Javascript.  I finally tracked it down to the web clipper extension; if I have the extension installed Safari stalls and, bizarrely, the extensions preference pane is blank apart from the "Automatically update extensions..." checkbox and "More extensions" button.  If I delete it (by removing it from ~/Library/Safari/Extensions because the preference pane is hosed) then everything is good.

Anyone else seen this behaviour?  Conscious it could be an odd interaction with another extension or plugin, but I only have 2 other extensions (1Password and ClickToPlugin) and the stalling happens even if I disable plugins. 

[AJ16S 0]

A quick update to yesterday's post.  Just checked on my MacBook Air running Safari 10.0.2 (same version of El Capitan) and I get no misbehaviour with the same extensions and plugins, so maybe it's related to the Safari 10.0.3 version.

[trentrocker 0]

Webclipper has been slow and constantly stalls ever since I remember using it. Jesus christ Evernote get your shit together.....