Blank page when moving site

I've just moved my site to a new server. It was functioning perfectly on the old server and I followed the instructions in the tutorial (https://www.zen-cart.com/tutorials/index.php?article=100) to the letter. It all worked fine up to the point where I uploaded the old files and overwrote the new installation. I am getting a blank page when I go to the store and when I try to use the fix_cache_key I also get a blank page. The admin section is working fine, and the database has all uploaded correctly. I tried reuploading all files in case there had been an error during the upload but that hasn't worked either. Does any one have any ideas please?
Thanks

If you are using any SEO mods you might want to take a look the htaccess folder also double check your upload it can be corrupted if you have a lot of files.

It was the SSU that was messing it up. I've removed that for the time being and will reinstall later, but I can now find the site. Thanks
for your help :)