The output of "fileimagename.txt" instead of "file imagename.txt" was corrected in 2.15,
commit: https://github.com/jenkinsci/parameterized-trigger-plugin/commit/5f243693cec9ceea46f085e58afac949e6cf9ac5

Is the checkbox "Trigger build without parameters" checked?
If this is checked the downstream project will always be started even if the file is missing so this is not an error
Section of code providing behaviour

If it still occurs please comment with more actual configuration you have.
preferable job's config.xml file if possible.

Which Version of the plugin 2.14? from the description bug mentioned above

Is this in the Postbuild section or as a build step?

How are you defining the "Parameters from a properties file" item,
Is this a hard-coded string or is it a ENV variable that is being expanded?

Is the checkbox "Trigger build without parameters" checked?

Fixed as part of correction for JENKINS-15834

I am running Jenkins 1.480.3 (LTS) and for me everything works.
Specifically I tested with:

• Trigger parameterized build on other projects
• Trigger build withoput parameters [ ] (not checked)
• Some predefined parameters
• Some from a file (with Don't trigger if any files are missing [x] checked.)

=> If the file is missing, downstream build is correctly not triggered.

@Martin
I assume that you are using 2.17 version of the plugin which has the fix indicated in JENKINS-15834.

Fixed in 2.17