Same problem here.
same problem here
We are aware of Flash Player hanging at 25% (download phase) on OS X 10.10 and are working to resolve the issue. If you have anti-virus protection enabled, please disable the anti-virus protection, which appears to be interfering with the download process. Alternatively, you can use the offline installer posted at the bottom of the Installation problems | Flash Player | Mac page in the 'Still having problems' section.
If you don't have anti-virus protection enabled, you're issue is different and we'd appreciate more information (please see Read Before Posting: How To Get A Useful Answer To Your Question for information to provide.
Thank you! Tried again and this time it worked!