Apple's built-in support for the PDF format has allowed for a number of programs to easily implement its use. Safari is one of these applications, and when you click on a PDF link you should be able to view PDFs without having to load any plug-ins or other software. Despite this, a number of people are having problems viewing PDFs in Safari, in which the browser will show a blank white or black screen instead of the selected PDF file.
This problem can happen for a variety of reasons, the most prominent of which are issues with Adobe's "Reader" plug-in. Adobe has had its "Adobe Reader" (Acrobat Reader) plug-in available for the Mac long before Safari and OS X were available, and has maintained development of it. It is required to view PDFs in some other browsers besides Safari, which makes it a required installation for some people.
Troubleshooting Adobe's plug-in
If you are unsure whether or not you have the Adobe plug-in installed, go to the "Help" menu in Safari and choose "Installed Plugins" to see if it is available in the list. If so, you can try troubleshooting it with the following suggestions:
Try 32-bit mode
The Adobe plug-in requires you to run Safari in 32-bit mode, since it has not been developed for 64-bit mode. Try ensuring Safari loads in 32-bit mode to be sure the plug-in is properly loaded, by getting information on the program and checking the "Open in 32-bit mode" option.
Update Adobe Reader
Try installing the latest version of Adobe Reader, which should install the latest version of the plug-in that might overcome various bugs, and which may contribute to this problem: http://get.adobe.com/reader/
Check for duplicates
If you have duplicate versions of the Adobe Reader plug-in installed, you may run into this problem. Go to the following directories, remove all instances of Adobe-related plug-ins, and then reinstall the latest version of Adobe Reader. The plug-ins should be in one or both of the following directories:
/Macintosh HD/Library/Internet Plug-Ins/
Set PDFs to be read by Adobe
Some people have had success by setting PDF files to be opened by Adobe applications instead of Apple's "Preview" or other applications. To do this, right-click a PDF file and get information on it. Then choose "Adobe Acrobat Pro" or "Adobe Reader" from the drop-down menu in the "Open With" section, and click the "Change All..." button.
Troubleshooting all plug-ins
You can try troubleshooting all of your Safari plug-ins by disabling them. To do this, go to Safari's preferences, and in the "Security" section deselect the option to "Enable plug-ins." Then try viewing a PDF again, which should be done solely with the built-in PDF renderer. If this works, then you can further troubleshoot your plug-ins by removing them from their respective "Internet Plug-Ins" folders and relaunching Safari to test your PDF files again. Provided you are able to view the PDFs properly, add your plug-ins back one by one and test Safari again with each.
Safari's default set of plug-ins includes the following list, which can be removed for troubleshooting purposes, but should be replaced when you are done isolating the problem.
While plug-in errors are most likely the root cause for this problem, you may also benefit from other maintenance routines as well.
PDFs may sometimes be rendered with the available system fonts, and if there are problems with your Fonts then both Adobe Reader and Apple's PDF technologies may not display them properly. Fonts can be rather frustrating to troubleshoot, but at least use Font Book to run a validation on those in your system. Open the program, press Command-A to select all fonts, and then choose "Validate Fonts" from the "File" menu. Also be sure to check for and remove duplicate fonts in your system. As with plug-ins, fonts are stored both in the global and user libraries, so check the following locations:
There are also system fonts, which are available in the /System/Library/Fonts/ folder, but these should not be touched since they are required by core system processes.
Empty caches and cookies
Beyond fonts, try general Safari troubleshooting by using the "Reset Safari" option in the "Safari" menu to empty the cache, delete cookies, and perform other maintenance routines. You may also consider removing Safari's preference file, which is called "com.apple.Safari.plist" and is located in the /username/Library/Preferences/ folder.
We thank MacFixIt readers "Dorinda" and "John" for contacting us about this problem.