Some of the issues I ran into include (but aren't limited to):
- Files and folders located in counterintuitive locations. Random files that ended up in some locations "just because". After a few years of working that job I knew where certain things were through tribal knowledge.
- Wading through files and documents that were years old. If SharePoint has a system in place that deletes files above a certain age, we didn't have anything like that set up.
- Dealing with a complicated access/security system, that restricted some users from seeing some pages.
- Having to make the intranet pages "work" with IE11. A good chunk of employees preferred using IE11 as their browser of choice so we couldn't not work on compatibility.
- Once, I accidentally moved in-progress HTML and JS files into a prod folder and one of the pages broke in prod. Fortunately it was after hours and I was able to retrieve the original files from GitHub.
- Major performance issues on some of the more data-heavy pages.
- Users not seeing links to docs because they was checked out (like library books), usually by one person with credentials different from everyone else.
That was Job 1 and I'd hoped to never touch SharePoint again. I'm on Job 3 now and I grimaced when I saw that the company used it as its intranet. I'd hate to be on the team responsible for maintenance.