Hello,

I have tested & confirmed this problem on multiple Apple computers, all running MacOS Sierra.
It's happening on a Mac Pro desktop computer, a fresh install MacBook Pro 2017, and a fresh install MacBook Air.

Steps to reproduce:

1. Download EncryptPad
2. Open EncryptPad0_3_2_5.dmg file and copy the EncryptPad application into the Applications folder
3. Launch EncryptPad from the Applications folder
4. Right click on EncryptPad in the Dock, and press "Keep in Dock"
   (Alternatively, rearrange the EncryptPad icon in the dock so that it auto-keeps)
5. Reboot MacOS
6. EncryptPad icon in dock is now a QUESTION MARK and is unusable, and unlaunchable.

Also: If you attempt to drag and drop EncryptPad from the Applications folder into the Dock, it will not work correctly: You will see an EncryptPad icon in the dock, but when you click on this icon a different EncryptPad will open (so that you see 2 separate EncryptPad icons), and the one you clicked on will not be running.