Hi,
I was having the same problem. I am with 1&1, and was frustrated that after uploading my pictures to NextGen, the Create New Thumbnails step got stuck at 0%. I did many google searches and found something that resolved my problem! Now NextGen is working fine:
Add this line of code at the end of the .htaccess file:
AddType x-mapp-php5 .php
AddHandler x-mapp-php5 .php
I don′t really know what it does, but it worked!
This is our site:
https://www.iglesiacristianabautista.com
Still working on it!
I also added the imageflow plugin. Here is where you can find it:
https://www.travel-junkie.com/geeky-stuff/wp-plugin-nextgen-imageflow/