As an old NOF user I recently purchased a V11 upgrade. I was taken to the download page where the upgrade download was listed twice. The download names varied slightly but both implied an upgrade exe file. ( NOF_11_Upgrade_EN.exe and NOF11_EN_Upgrade.exe ).

When downloaded they both are described as version (this is also known as build number) although they are different files, eg they are of different size. ( NOF_11_Upgrade_EN.exe is 130MB and NOF11_EN_Upgrade.exe is 134MB)

The larger file (NOF11_EN_Upgrade.exe) will install but will not work properly. Under Win 7 64 bit it will not allow yoou to create a site with a not enough disk space message (I had over 100GB free). It will also fail to open sites created with previous versions correctly. The latter includes not being able to use the templates.

The smaller file (NOF_11_Upgrade_EN.exe) will install and work properly. The problems all disappear.

I have provided this information to NOF so it may be corrected soon and the wrong exe removed. Until then just make sure you install the correct exe file.