There is a bug in the kompozer tool that causes a pathname error when an attempt is made to open a document, whilst another session of kompozer is open:
Supposing you have two files:
Open kompozer for the first document:
cd /rhubarb/foobar/ kompozer foo.html
Now minimize that session and try to start another session of kompozer:
cd /rhubarb/barbar kompozer bar.html
Alert: The file /rhubarb/foobar/bar.html cannot be found. Please check the location and try again.
Huh! The file is in the current /rhubarb/barbar directory. Why is it looking at the location used in the unrelated first session?