I have literally thousands of objects in a scene, H’d them away to focus on a few small things and tried to Alt+H them back but nothing happens. I have spent a half hour Googling solutions and still, nothing. This is extremely frustrating. I really do not want to have to spend the next half hour clicking thousands of little eyeballs. Please help. Win7 64bit GTX780 16GB RAM
How? You’ve given us nothing to work with.
I’ve described the problem and told you my basic system specs. You call that nothing? What else am I supposed to give you?
I pressed H to hide things and tried to get them back with alt+H. Nothing happens. Googled How to undhide or show all in blender. All answers I found said hit alt+H. I even found several hits that say there’s a bug where alt+H doesn’t work but those are all older hits so I figured if that was a bug, it would be resolved by now.
Hitting show all layers from the view menu doesn't work either. Also tried H and alt+H in a simpler scene thinking that perhaps Blender doesn't like that many objects in a scene. No luck.
Solution found: Changed “Clear restrict view” to Ctrl+alt+H. I don’t know what that worked. Perhaps alt+H was conflicting with some other hotkey. Dunno. But it worked. So nevermind, I suppose. I just hope I didn’t screw something else up in the process.
Yup. As linked in my signature https://blenderartists.org/forum/showthread.php?322623-How-to-ask-questions-effectively-on-blenderartists-org-support-forum&p=2547191&viewfull=1#post2547191
And everything else that you think might actually be related to Blender not behaving like it’s supposed to, like not using Blender from blender.org, version but that will be visible in the screenshot, using different key configuration than the default
I didn’t really think screenshots were necessary since the problem is very straightforward and I am using the most recent stable version of Blender from Blender.org. It’s freeware. Stuff like this happens sometimes I suppose. I can’t be too mad. Not like I can demand my money back. 
Besides, it worked out in the end so there’s that.
“clicking thousands of little eyeballs” - next time just press mouse button over one and drag over the rest of eyeballs (or cameras).
I wasn’t exaggerating when I said “thousands.” Instead of clicking, it would be: click-drag, scroll scroll scroll, click-drag, scroll scroll scroll… for a long time. I’m coming out of zbrush with nanomesh to geometry baskets. Could have just grouped it all inside of ZBrush but I figured it would be as easy in Blender. Aside from that, things have been going smoothly.
Pattern select, group, use Outliner’s Group view visibility… But yes, i get the overall picture.
Yeah… so I learned several new things from that. 
Thanks so much. I’m new to Blender… well, sort of. I’ve almost exclusively only ever used it for rendering. My work flow is a little different from most people’s (at least I’m pretty sure?) But recently I’ve been delving deeper into Blender- modeling, texturing, etc. So I appreciate the tips. Many thanks.
A faster way is pressing tilde (`), press A to select all, then Alt+H. Note that this will un-hide on all layers.
Yea, only if the thread title wasn’t “Alt+H not working”