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Chrome 66 causing errors on some Umbraco sites

If you're using Chrome, this might effect you now, or very soon - we've got a solution for you.

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Written by Jacob Midtgaard-Olesen

On April 17th, Google released Chrome version 66. Following this release, issues in Umbraco has been identified which will cause certain functions to break. This means that very soon, as Chrome automatically upgrades yours or your editor’s brower, you might run into problems in the back office. We’ve got both a quick fix for you and on Tuesday we are releasing a patch to fix the issues we’ve identified so far - automatically for Cloud and manually for non-cloud:

What you might experience:

The Google released Chrome version 66 release includes new trimStart and trimEnd functions. Umbraco has used and shipped with these functions since Umbraco 7.0.0. The new Chrome release overruled the methods built into Umbraco and the Chrome version has a different implementation than the Umbraco version. This can break some things in Umbraco, we have so far identified issues with:

  • The Color Picker datatype in Umbraco can no longer be configured to add new colors

  • Inability to use the Doc Type Grid editor package

  • Other custom plugins for Umbraco cause errors and are no longer working


We expect to see more issues crop up once more people start upgrading to Chrome 66. We will therefore keep updating this blog post with the latest identified issues.



On Tuesday April 24 2018 we will release patch updates for Umbraco 7.8.x, 7.9.x and 7.10.x - these new Umbraco versions eliminate the problem by overriding these trim functions built into Chrome.


The quick/temporary fix: Until the update has been rolled out, you can use a different browser to avoid the issues. This means that you are able carry on with your work in Umbraco.

Umbraco Cloud users:

Umbraco Cloud users currently on version 7.8 and above will receive an automatic upgrades on Tuesday.

Umbraco Cloud users below 7.8 will also receive an automatic update to a single file in their website, the file ~/Umbraco/lib/umbraco/Extensions.js will have a small update in 2 places, to make sure we override Chrome’s implementation of the trim methods. will also receive an automatic upgrade as soon as possible.

Umbraco users not on Cloud

Umbraco users who are not on Cloud can of course also expect patch updates to be available on Tuesday April 24 for 7.8+ releases.


Manual patching for Umbraco versions below 7.8

If your site is running on a version lower than 7.8 and is experiencing 404 errors in the backoffice or problems with the color picker datatype, you can manually update the  ~/Umbraco/lib/umbraco/Extensions.js file. The changes that need to be made are listed in the "Manual patching / workaround" section of the description of the issue here: 

Details and questions

All the details of the problem and fix are listed in the following issue:


We will update this blog post if more issues should occur due to the Google Chrome update.

If you have any questions, make sure to add them to the issue above and we will try to get back to you as quickly as possible.


Thanks and a big H5YR to community members Janae Cram and Lee Kelleher for discovering and making us aware of this issue! 🙌

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