One of the problems that regularly occurs is the inability to print a transaction or a report.
However, this is usually caused by your browser's pop-up blocker.
Disabling the pop-up blocker is different for each browser, and is also dependent on whether or not you're using mobile or desktop.
The following are links to disable the pop-up blocker for common browsers:
Chrome - Block or allow pop-ups in Chrome
Safari - How to block pop-ups in Safari (obviously, you'll want to allow them for Method:CRM instead)