The most prevalent issue with Chrome's PDF viewer occurs when it downloads PDFs automatically, which can be pretty annoying if you prefer previewing documents prior to saving them locally. However, it doesn't take long to get the problem fixed, so let's see how.
Disable PDF Downloads
Chrome has a built-in setting that forcibly downloads PDFs instead of opening them. While this setting is usually disabled by default, you may have accidentally turned it on, or perhaps a third-party add-on modified it instead. To check if this is the case, you need to dive into the Chrome Advanced Settings panel.
Step 1: Open the Chrome menu, and then click Settings.
Step 2: Scroll down, and then click Advanced.
Step 3: Under the Privacy and Security section, click Content Settings.
Step 4: Scroll down, and then click PDF Documents.
Step 5: If turned on, disable the switch next to Download PDF Files Instead of Automatically Opening Them in Chrome.
That's it. PDFs should now display within Chrome instead of downloading automatically.