Hi jos@bosch
Nothing in the theme update would cause issues with W3. It is a performance/caching plugin, and something that needs to be maintained with changes to your site.
When you update the theme, the files will be replaced, but it’s likely that W3 will cache a lot of the stylesheet/scripts. If you don’t clear that cache, then there is a high chance that it be out of date.
Nothing to do with the theme here, just make sure in the future that you go through the proper steps to clear all old cache files when you make a theme update.
– Ed
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