Adobe Illustrator CS5: Windows are blank. Unable to save out .pdf

Don,

If no brighter suggestions appear, and if you have not made any OS upgradesthat may have caused strangenesses, it may be worth trying 4) or 6) on the list.

If things that should work simply refuse to (all possibilities exhausted including the A) - C) below (and carefully making sure you are performing (all) the needed things)), you may try (the relevant part(s) of) the list 1) - 6) below.

Sometimes, (certain) things may fail or stop working for no apparent reason. When the (other) possible reasons/cures fail to work, it may be some kind of (temporay or permanent) corruption, or even some inconvenient preference setting(s), which may be cured with something on the following list set up in an attempt to provide a catchall solution for otherwise unsolvable cases. It starts with a few easy and harmless suggestions 1) and 2) for milder cases, and goes on with two alternative ways 3) and 4) of resetting preferences to the defaults (easily but irreversibly and more laboriously but more thoroughly and also reversibly), then follows a list 5) of various other possibilities, and it ends with a full reinstallation 6). If no other suggestions work, or if no other suggestions appear, you may start on the list and decide how far to go and/or which may be relevant.

The following is a general list of things you may try when

A) The issue is not in a specific file,

B) You have a printer correctly installed, connected, and turned on if it is physical printer (you may use Adobe PDF/Acrobat Distiller as the default printer with no need to have a printer turned on, obviously you will need to specify when you actually need to print on paper), and

C) It is not caused by issues with opening a file from external media (see at the bottom).

You may have tried/done some of them already; 1) and 2) are the easy ones for temporary strangenesses, and 3) and 4) are specifically aimed at possibly corrupt/inconvenient preferences); 5) is a list in itself, and 6) is the last resort.

If possible/applicable, you should save current artwork first, of course.

1) Close down Illy and open again;

2) Restart the computer (you may do that up to at least 5 times);

3) Close down Illy and press Ctrl+Alt+Shift/Cmd+Option+Shift during startup (easy but irreversible);

4) Move the folder (follow the link with that name) with Illy closed (more tedious but also more thorough and reversible), for CS3 - CC you may find the folder here:

https://helpx.adobe.com/illustrator/kb/preference-file-location-illustrator.html

5) Look through and try out the relevant among the Other options (follow the link with that name, Item 7) is a list of usual suspects among other applications that may disturb and confuse Illy, Item 15) applies to CC, CS6, and maybe CS5);

Even more seriously (this may be serious because you may need to restore plugins and whatnot afterwards if you have customized things), you may:

6) A) Uninstall (ticking the box to delete the preferences if applicable), B) run the Cleaner Tool (if you have CS3/CS4/CS5/CS6/CC), and C) reinstall. You may try without step B), but sometimes it is needed, because otherwise things may linger.

As it appears from this thread, it may be worth repeating this if it fails to help the first time:

https://forums.adobe.com/thread/2283530

To uninstall:

https://www.adobe.com/cfusion/search/index.cfm?loc=en_us&term=uninstall&cat=support&product=illustrator&self=1

Cleaner Tool:

http://www.adobe.com/support/contact/cscleanertool.html

External media: It is generally recommended here to open/save from/to own hard disk, and to copy from/to networks and removable media. You may be lucky (for a while), but the chances of file corruption and other unpleasantnesses are immensely greater when you use anything but the harddisk, and it is better to be safe than sorry.

In addition to the (far greater) risk of file corruption, some issues are mentioned here:

http://helpx.adobe.com/illustrator/kb/illustrator-support-networks-removable-media.html

To have a network actually work may require some work.

Be careful that you do not mix Macs and Windows on a network: You must use a Mac server with Mac machines and a Windows server with Windows machines.

If you transfer by external means it is always safest to zip/compress the file to avoid corruption.