During a recent project using SharePoint 2013 Online as part of an E1 Office365 subscription, I stumbled across a puzzling issue that I was sure hadn’t been there days before.
When viewing search results within SharePoint, be it using a search centre or out of the box search results page, the result preview call-outs were not working when using the Firefox browser. The call-outs worked in Internet Explorer, Chrome and Safari, but not Firefox.
My immediate thought was that I’d affected something based on my project customizations. However, I realized that the default search site collection provided with SharePoint Online had not been customized yet.
To try and clarify what was going on, I tested the same search queries in all 4 major browsers, I then used in-built browser developer tools to see if there was anything immediately wrong in any script processing. There was nothing wrong on page load. All I could obviously see at this stage was the absence of the call-out.
After the first instance of this, I logged in to an alternative SharePoint 2013 Online tenant, but could not reproduce the issue. I put the problem on the back-burner for two weeks as I had plenty to be getting on with. It was only when I returned to search related tasks that I carried on troubleshooting. This time, the other tenant also exhibited the same issue in Firefox.
Interestingly, call-outs in other areas of SharePoint 2013 were functioning, for example when hovering over a user for presence and contact card. But this one was bugging me, so on to the next step.
I contacted Microsoft support by raising a new ticket in the Office 365 Admin center, explaining the issue and outlining troubleshooting steps I had taken. I wasn’t expecting a quick turn-around, but that afternoon I had a call from a support technician.
Over the phone and using a remote desktop view session, we worked through similar troubleshooting steps, but also resetting Firefox, ensuring the latest Microsoft Office 2013 plugin version was installed.
- “Use of Mutation Events is deprecated. Use MutationObserver instead.” – mquery.js – https://developer.mozilla.org/en-US/docs/Web/Guide/Events/Mutation_events
This then seemed to cause a knock on effect with other script functions such as the following:
- “TypeError: document.defaultView.getComputedStyle(…) is null” – init,js
- “TypeError: b is null” – WordViewer.js
The Current Situation
The Microsoft support technician stated that unfortunately “Mozilla have replaced this service with “MutationObserver”, however, the codes have not been updated on either Mozilla or Microsoft side at the moment. See this link: https://developer.mozilla.org/en-US/docs/Web/API/MutationObserver for Mozilla explanation.”
Less than an ideal situation obviously, and I am fairly certain that it has been caused by an update to SharePoint online, as the issue in Firefox can be replicated in multiple versions. However, due to the nature of updates to both Firefox and Office 365 being frequent and certainly in the case of OFfice365 being out of user control, we cannot currently do anything about it.
Hopefully the issue will be logged officially and it will come to the attention of someone sooner rather than later to be rectified.