ok, one last change before going to bed.
Maybe there is text before and after the link, in such a case
it would break the logic. Here a solution which gets the link text only.
Replace callbackHOTSPOT… with this one

def callbackHOTSPOTRELEASECLICK(args):
    __pos = args['position']
    __style_id = editor.getStyleAt(__pos)
    __word_start = None
    __word_end = None
    
    _p = __pos
    while True:
        __word_start = _p
        if editor.getStyleAt(_p) != __style_id:
            break
        _p -= 1

    _p = __pos
    while True:
        if editor.getStyleAt(_p) != __style_id:
            __word_end = _p
            break
        _p += 1
    
    link_text = editor.getTextRange(__word_start, __word_end+1) 
    
    if file_identifier in link_text and position_seperator in link_text:
        global file_to_load
        global line_in_file
        file_to_load, line_in_file = link_text[link_text.find(file_identifier):].split(position_seperator)
        file_to_load = file_to_load.replace(file_identifier, '')
        file_to_load = os.path.normpath(file_to_load)
        notepad.open(file_to_load)

Good Night.

Cheers
Claudia

and if your program starts counting lines from 1 instead of 0 you need to
change the line

editor.gotoLine(int(line_in_file))

to

editor.gotoLine(int(line_in_file)-1)

So, hopefully this was the last update today ;-)

Cheers
Claudia

ok, found the culprit, we need to use HOTSPOTRELEASECLICK instead HOTSPOTCLICK. The following should work.

import os

file_identifier = 'file:///'
position_seperator = '#'
file_to_load = None
line_in_file = 0
 
def callbackBUFFERACTIVATED(args):
    global file_to_load
    if file_to_load is not None:
        current_file = notepad.getBufferFilename(args['bufferID'])
        if file_to_load.lower() == os.path.normpath(current_file).lower():
            editor.gotoLine(int(line_in_file))
            editor.verticalCentreCaret()
            file_to_load = None


def callbackHOTSPOTRELEASECLICK(args):
    line_of_link = editor.lineFromPosition(args['position'])
    link_text = editor.getLine(line_of_link)
    if file_identifier in link_text and position_seperator in link_text:
        global file_to_load
        global line_in_file
        file_to_load, line_in_file = link_text.split(position_seperator)
        file_to_load = file_to_load.replace(file_identifier, '')
        file_to_load = os.path.normpath(file_to_load)
        notepad.open(file_to_load)

editor.callback(callbackHOTSPOTRELEASECLICK, [SCINTILLANOTIFICATION.HOTSPOTRELEASECLICK])
notepad.callback(callbackBUFFERACTIVATED, [NOTIFICATION.BUFFERACTIVATED])

Cheers
Claudia

because the latest python script version tends to fail if installed by plugin manager
just double check if it has correctly installed on your side. Plugins->PythonScript->Show Console should report something like

Python 2.7.6-notepad++ r2 (default, Apr 21 2014, 19:26:54) [MSC v.1600 32 bit (Intel)]
Initialisation took 145ms
Ready.

If this doesn’t appear or you get an error download the MSI package and reinstall it.

Once done, create a new script by Plugin->PythonScript-New Script
name the file startup.py and paste the following content into it.

import os

file_identifier = 'file:///'
position_seperator = '#'
file_to_load = None
line_in_file = 0
 
def callbackBUFFERACTIVATED(args):
    global file_to_load
    if file_to_load is not None:
        current_file = notepad.getBufferFilename(args['bufferID'])
        if file_to_load.lower() == os.path.normpath(current_file).lower():
            editor.gotoLine(int(line_in_file))
            editor.verticalCentreCaret()
            file_to_load = None


def callbackHOTSPOTCLICK(args):
    line_of_link = editor.lineFromPosition(args['position'])
    link_text = editor.getLine(line_of_link)
    if file_identifier in link_text and position_seperator in link_text:
        global file_to_load
        global line_in_file
        file_to_load, line_in_file = link_text.split(position_seperator)
        file_to_load = file_to_load.replace(file_identifier, '')
        file_to_load = os.path.normpath(file_to_load)
        notepad.open(file_to_load)

editor.callback(callbackHOTSPOTCLICK, [SCINTILLANOTIFICATION.HOTSPOTCLICK])
notepad.callback(callbackBUFFERACTIVATED, [NOTIFICATION.BUFFERACTIVATED])

Take care about indention, python is strict about it (don’t know if you familar with python language).

One additional step -> Plugins->PythonScript->Configuration
change Initialisation from LAZY to ATSTARTUP.

Done - every time you start npp this script gets executed automatically.

What does the script?
It registers a callback for hotspotclick and bufferactivated notification. Once you click
on a link the callback gets executed and tries to get the text from the link.
If it starts with file:/// and has # in the line it is supposed to be a file link and gets
the details, file_to_load and line_in_file. Then it asks notepad to open that file.
If this is successful, npp sends a notification (bufferactivated) once the buffer has been loaded. Now the second part starts - it gets checked if this is the file we want
and if so we goto the line in question.
Currently I have no windows environment to test but under Linux(wine)
I do have a strange behavior. When the goto line is called some text before that
line gets selected. I hope this isn’t an issue under windows.

Cheers
Claudia

I don’t think it is possible using native npp functions.
What I can think of is using a scripting language like python script or lua script
and using the hotspotclick notification send by scintilla.
We would receive the location/position of this click event and could get the text
from that line. If your format is always the same I assume we could prepare such a script.
Let us know if you wanna go this way.

Cheers
Claudia