com.jacob.com.ComFailException: Invoke of: Open Source: Description

[yujunchengg]

My program runs in the following environmen
windows server 2016 Standard 64 bit
Microsoft Office Professional 2016
jdk version: 1.8.0 (build 1.8.0_221-b11)
jacob version: 1.20
The program code is as follows
public static FileConvertResult ppt2PDF(String pptfile, String pdffile){
if(Files.exists(Paths.get(pdffile))){
return new FileConvertResult(true,false);
}
synchronized (pptfile.intern()){
FileConvertResult result = new FileConvertResult(true,false);
if(Files.exists(Paths.get(pdffile))){
log.info("current thread: {} do not need to execute ppt2PDF method, because other thread has execute ppt2PDF method",Thread.currentThread().getName());
return result;
}
ActiveXComponent ppt = null;
Dispatch presentations = null;
try {
ComThread.InitMTA(true);
ppt = new ActiveXComponent("PowerPoint.application");
Dispatch.put(ppt.getObject(), "DisplayAlerts", new Variant(false));
presentations = ppt.invokeGetComponent("Presentations").invokeGetComponent("Open", new Variant(pptfile));
Dispatch.invoke(presentations, "SaveAs", Dispatch.Method, new Object[] {pdffile , new Variant(32) }, new int[1]);
} catch (Exception e) {
log.error("-------------ppt2PDF occurred exception----------");
String message = e.getMessage();
result.setSuccess(false);
result.setNeedReconvert(true);
result.setDescription(message);
/if(null!=message){
if(message.contains("Description: ")){
result.setNeedReconvert(false);
}
}/
log.error(result.getDescription(), e);
} finally {
try {
if (ppt != null) {
ppt.invoke("Quit");
}
} catch (Exception e1) {
log.error(e1.getMessage(),e1);
} finally {
if (presentations != null){
presentations.safeRelease();
}
if (ppt != null){
ppt.safeRelease();
}
ComThread.Release();
}
}
return result;
}
}

Strangely enough it can work well on Windows server 2012,but on Windows server 2016,it occurred exception，exception detail message is that:
com.jacob.com.ComFailException: Invoke of: Open
Source:
Description:

at com.jacob.com.Dispatch.invokev(Native Method)
at com.jacob.com.Dispatch.invokev(Dispatch.java:625)
at com.jacob.com.Dispatch.callN(Dispatch.java:453)
at com.jacob.activeX.ActiveXComponent.invoke(ActiveXComponent.java:476)
at com.jacob.activeX.ActiveXComponent.invokeGetComponent(ActiveXComponent.java:391)

[EJP286CRSKW]

Where did you get new Variant(32) from? It's supposed to be 0 or -1. https://learn.microsoft.com/en-us/office/vba/api/powerpoint.presentations.open and https://learn.microsoft.com/en-us/dotnet/api/microsoft.office.core.msotristate?view=office-pia