A while ago, I wrote an SPFx Application Customizer that allows you to insert custom CSS on your SharePoint modern pages and posted about it.

The solution is now a sample in the SharePoint SharePoint Framework Extensions Samples & Tutorial Materials repo.

I received lots of feedback, comments and questions about the article so I decided to write an updated article to answer the most frequently asked questions.

I have since updated the solution to SPFx 1.8 and created a simple automated deployment script to (hopefully) reduce issues.

When migrating from SharePoint on-premises to SharePoint Online/Office 365, you may find that some users have a checked-out file called `spcommon[1].png`. If you ask users about it, they’ll have no idea what you’re talking about.

As it turns out, this isn’t a bug. It is possible for users to check-out this file without knowing they did it.

People don’t always find content by searching. For example, if you’ve ever tried to find something but didn’t know what keyword to use in your search query, you’ll appreciate how challenging it can be. Find the 3 ways users find content and how your Information Architecture can help people find what they need — even when they don’t know what they’re looking for.

In software projects, we have a tendency to repeat the same mistakes over and over again.

Stakeholders ask for estimates. Usually something along the lines of “we don’t know what we want. When can you have it done and how much will it cost?”.

Find out how the cone of uncertainty and agile planning can help you answer these questions and help you break that endless cycle of pointless estimates.