Chrome and Firefox are deprecating modal dialogs which presents an issue for Microsoft Dynamics CRM users. This started appearing with Chrome 37. It was deprecated in 35 and then in 37 it was turned off by default. There isn’t a permanent fix at this time, only a temp work around that will work until the middle of 2015.
The CRM team is working on a solution but it will require all the model dialogs to be fixed in new releases and also create patches for previous versions of CRM.
Of course the easy alternative is to upgrade to IE 11.
The error looks like this:
There was an error with this field’s customized event.
Although not specific to CRM as it applies to all modal dialogs, you can use this KB article to fix your copy of Chrome: http://support2.microsoft.com/kb/3000002