Groovy script stopped working with import error

I use a groovy script to highlight peptides in a sequence alignment. It reads a txt file and and basically searches peptides and colours them differently.
This worked fine for a long time, but now out of a sudden, the script reports problems in the import commands.

I can't remember updating either Jalview nor Java, but the problem is now on different computers where the script worked fine before.

The error message is:

groovy.lang.MissingPropertyException: No such property: currentAlignFrame for class: jalview.bin.Jalview
Possible solutions: currentAlignFrame

at highlight_peptides.run(highlight_peptides.groovy:6)


And the groovy script:

import jalview.util.ColorUtils
import jalview.datamodel.SequenceFeature
import jalview.schemes.FeatureColour
import jalview.analysis.Finder

def af = jalview.bin.Jalview.currentAlignFrame
def av = af.viewport
def fr = af.featureRenderer
def finder = new Finder(av)

new File("/Users/user/Downloads/jalview/motifs.txt").eachLine
{
  line ->
   if (!line.startsWith('#'))
   {
    tokens = line.split("\\t")
    motif = tokens[0]
    featureName = tokens[1]
    featureColour = ColorUtils.parseColourString(tokens[2])
    featureScore = (tokens.length < 4 ? 0 : Float.parseFloat(tokens[3]))
    fr.setColour(featureName, new FeatureColour(featureColour))
    finder.findAll(motif, false, false, false)
    matches = finder.searchResults.results
    matches.each
    {
        sf = new SequenceFeature(featureName, motif, it.start, it.end, featureScore, null)
        it.sequence.addSequenceFeature(sf)
    }
  }
}
av.setShowSequenceFeatures(true)
af.alignPanel.paintAlignment(false, false)


So, somehow the currentAlignFrame is no longer available?
Where can I get some help on this issue and where is the best place to ask?
Thanks in advance
Mario