Caused: BUG! exception in phase 'semantic analysis' in source unit 'WorkflowScript'

I have written a method that suppose to read the key value but this gives an error while running via jenkinsfile

here's the code (ScanMethods.groovy):

package api.Scan

public static ScanPipeline(String VERACODE_API_ID, String VERACODE_API_SECRET, String failOnSeverity, String BaseFile) { 
  Map custom_block = [
    VERACODE_API_ID: VERACODE_API_ID,
    VERACODE_API_SECRET: VERACODE_API_SECRET,
    failOnSeverity: failOnSeverity, 
    BaseFile: "results.json"   
  ]

    Scan.scanload(custom_block)
}

Jenkinsfile

pipeline {
  agent any 
  options {
    buildDiscarder logRotator(artifactDaysToKeepStr: '', artifactNumToKeepStr: '', daysToKeepStr: '', numToKeepStr: '5')
  }
  stages {
    stage('Veracode Pipeline') {
       agent { label "default" }    
       steps {
          script {  
           ScanMethods.scan-veracode-pipeline(VERACODE_API_ID, VERACODE_API_SECRET, failOnSeverity, BaseFile)
        }
    }}
}
}

Error i have recieved:

org.codehaus.groovy.control.MultipleCompilationErrorsException: startup failed:
/var/jenkins_home/jobs/Test_pipelines/jobs/ankur-test/jobs/pipeline-scan-cit-cdw-jenkinsfile/branches/feature-T23D-4021.247156/builds/19/libs/ASTLib/src/api/ScanMethods.groovy: 11: Apparent variable 'Scan' was found in a static scope but doesn't refer to a local variable, static field or class. Possible causes:
You attempted to reference a variable in the binding or an instance variable from a static context.
You misspelled a classname or statically imported field. Please check the spelling.
You attempted to use a method 'Scan' but left out brackets in a place not allowed by the grammar.
 @ line 11, column 5.
       Scan.scanload(custom_block)
       ^

1 error

    at org.codehaus.groovy.control.ErrorCollector.failIfErrors(ErrorCollector.java:310)
    at org.codehaus.groovy.control.CompilationUnit.applyToPrimaryClassNodes(CompilationUnit.java:1085)
    at org.codehaus.groovy.control.CompilationUnit.doPhaseOperation(CompilationUnit.java:603)
    at org.codehaus.groovy.control.CompilationUnit.processPhaseOperations(CompilationUnit.java:581)
    at org.codehaus.groovy.control.CompilationUnit.compile(CompilationUnit.java:558)
    at groovy.lang.GroovyClassLoader.doParseClass(GroovyClassLoader.java:298)
    at groovy.lang.GroovyClassLoader.parseClass(GroovyClassLoader.java:268)
    at groovy.lang.GroovyClassLoader.parseClass(GroovyClassLoader.java:254)
    at groovy.lang.GroovyClassLoader.recompile(GroovyClassLoader.java:761)
    at groovy.lang.GroovyClassLoader.loadClass(GroovyClassLoader.java:718)
    at groovy.lang.GroovyClassLoader.loadClass(GroovyClassLoader.java:787)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:405)
    at org.jenkinsci.plugins.workflow.cps.CpsGroovyShell$TimingLoader.loadClass(CpsGroovyShell.java:170)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:405)
    at groovy.lang.GroovyClassLoader.loadClass(GroovyClassLoader.java:677)
    at groovy.lang.GroovyClassLoader.loadClass(GroovyClassLoader.java:545)
    at org.codehaus.groovy.control.ClassNodeResolver.tryAsLoaderClassOrScript(ClassNodeResolver.java:185)
Caused: BUG! exception in phase 'semantic analysis' in source unit 'WorkflowScript' The lookup for api.ScanMethods caused a failed compilaton. There should not have been any compilation from this call.

Please help in how to resolve this error in order to read the values