For what it is worth, I was unable to change to the Web and Print modules, and I was also unable to record new presets (though I had successfully done it many times before) though I could still use already created ones. I was baffled, but found a workaround using hints from this and other forums. Much thanks to those who provided me with a starting point as I never would have figured this out on my own.
My wife is a separate user on the same computer, and I tried switching our catalogues and preference files, ... nada. Looking at her folder structure under user/library/application support/adobe/lightroom, she had folders for Web Templates, Web Galleries, and Print Templates but I didn't. So, simply copying her folders (not creating new ones of the same name, which may still have worked) into my own lightroom directory worked.
Where I screwed up initially was tryiong to use my own presets under her install of lightroom and then creating new ones (which worked) but then trying to import them back into mine. I had the new presets working under my own install, but still couldn't create new ones under my own setup. Finally, I realized that it was the "Develop Presets" folder under my own install that was in some way corrupted and copied her Develop Presets folder into my own install and every thing was fixed. I could even copy the subfolders from my own Develop Presets folder directly back in without issue.
Hope this helps someone.
Shivam's solution worked for me, but I was not able to drag the Lightroom to the Desktop (it only copied the files to my Desktop, it did not move them). OS X Lion seems to be protecting that folder, so every change requred a password. I renamed the Lightroom folder to xLightroom. Then I created a new Lightroom folder (this was an essential step). When I next launched the Lightroom app it worked!!
Hey in order to acess library folder in lion osx you need to follow some diff steps
Try anyone of them.....