Overall I am very pleased with e-Newsletter. There is just one small bug that is very annoying.
I wanted to add my custom theme. I did this by copying one of the existing themes and renaming both the copied folder and the name inside the style.css file. When I am editing a Newsletter and switch to this theme everything is fine. The problem is when I save and then later edit a Newsletter with this theme. It always deactivates my WordPress theme and switches to the default theme. Just to be sure, I tried making a custom theme without changing anything except the name. I always get this error.
After much trying I finally decided to just edit one of the existing themes and that worked great. So I edited the Handwritten theme and got it working. However, the problem still comes back at times (only approximately one in fifty times). And it only ever happens when I click on "Edit" on the Newsletters screen.
I'm not sure if this is an error with the plugin or WordPress but the strange thing is that it only happens sometimes, it's not consistent. With custom themes it happens always, however.
It's be great if you could get one of the developers to look at it because I've seen some similar forum posts that report the same problem with the default theme being activated. I've halfway fixed the problem by changing the default theme to the theme I want, but the problem is that all widgets are deactivated whenever this happens.
Thank you for your help!