I recently did a fresh install of OSX Yosemite on my 2009 MacBook Pro, and reinstalled my most used software, including MAMP, for test installing sites locally. Prior to the OSX fresh install, I had no problems installing Newspaper demos on my MacBook Pro.
After the OSX Yosemite fresh install, I received the message “The link you followed has expired” when attempting to upload Newspaper9 into a WordPress test site.
After doing some research on the net, I determined the problem was most likely caused by the WordPress Maximum File Upload Size, which was set to 8mb by default. The Newspaper 9 file was 11 mb.
To increase the default WordPress Maximum file upload size, I added the following lines to .htaccess
php_value upload_max_filesize 64M
php_value post_max_size 64M
php_value max_execution_time 300
php_value max_input_time 300
This resolved the problem. This method was among several possible solutions I found at the following link:
NOTE: In order to see .htaccess in Mac Finder, you need to already have your system set to show hidden files. You will find instructions on how to do this at the following url. (It has info on how to show hidden files on versions other than Mavericks)