Hi,
this is a issue I am confronted since a few days and I have absolutely no idea how to fix this, thats why I am asking you 
I am on Manjaro KDE. On 3 PCs. Only on my main PC I discovered this issue:
I am opening my textfiles, markdown files, etc. with nano. Therefore I just doubleclick them in dolphin. I have /usr/bin/nano and “run in Terminal” associated with these file’s mimetypes…
The settings stayed the same and are 100% the same as on my 2 other PCs… Nevertheless, I have this strange issue:
When double clicking on the file, nano opens, but with an empty file (“Empty buffer”)… I can try what I want… delete those file “with lists” (under ~/.local/share/applications) and re-create them…
So… nano just does not open the file, but an empty one.
I discovered that vim does the same: when selecting vim from dolphin’s list… also an empty file.
I have no idea what could be wrong here… as I did not change something on my system… and on my two other PCs… these settings still work fine…
Any idea, friends?
Kind regards… and thank you