Compile Java error on PDFMergerUtility

Hi,

when I try to run my project, I get an compile error on teh PDFmergeUtility. (See below)

I have updated every module (CommunityCommons/ApplCloudServices/MxModelreflextion/RestServvices)in my project, the error remains :-(

Does anybody have an idea how I can fix this ?

Thanks!

Onco

ERROR:

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Buildfile: C:\Users\XXXX\Documents\Mendix\Plop\deployment\build_core.xml

compile:
    [javac] Compiling 549 source files to C:\Users\XXXX\Documents\Mendix\Plop\deployment\run\bin
    [javac] C:\Users\XXXX\Documents\Mendix\Plop\javasource\restservices\publish\RestServiceHandler.java:250: warning: '_' used as an identifier
    [javac]             String _) {
    [javac]                    ^
    [javac]   (use of '_' as an identifier might not be supported in releases after Java SE 8)
    [javac] C:\Users\XXXX\Documents\Mendix\Plop\javasource\apportaal\actions\JA_MergePDF.java:15: error: cannot find symbol
    [javac] import org.apache.pdfbox.util.PDFMergerUtility;
    [javac]                              ^
    [javac]   symbol:   class PDFMergerUtility
    [javac]   location: package org.apache.pdfbox.util
    [javac] C:\Users\XXXX\Documents\Mendix\Plop\javasource\apportaal\actions\JA_MergePDF.java:45: error: cannot find symbol
    [javac]         PDFMergerUtility  mergePdf = new  PDFMergerUtility();
    [javac]         ^
    [javac]   symbol:   class PDFMergerUtility
    [javac]   location: class JA_MergePDF
    [javac] C:\Users\XXXX\Documents\Mendix\Plop\javasource\apportaal\actions\JA_MergePDF.java:45: error: cannot find symbol
    [javac]         PDFMergerUtility  mergePdf = new  PDFMergerUtility();
    [javac]                                           ^
    [javac]   symbol:   class PDFMergerUtility
    [javac]   location: class JA_MergePDF
    [javac] Note: Some input files use or override a deprecated API.
    [javac] Note: Recompile with -Xlint:deprecation for details.
    [javac] Note: C:\Users\XXXX\Documents\Mendix\Plop\javasource\com\mendix\core\Core.java uses unchecked or unsafe operations.
    [javac] Note: Recompile with -Xlint:unchecked for details.
    [javac] 3 errors
    [javac] 1 warning

BUILD FAILED
C:\Users\XXXX\Documents\Mendix\Plop\deployment\build_core.xml:27: Compile failed; see the compiler error output for details.

Total time: 5 seconds

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