RStudio - XLConnect - load xlsx workbook - rstudio

Question

when running the following code:
library(forecast)
Sys.setenv(JAVA_HOME='C:\\Program Files (x86)\\Java\\jre7') # for 32-bit
library(XLConnect)
wb <- loadWorkbook(filename = 'C:/Program Files/R/R-3.2.3/library/XLConnect/demoFiles/mtcars.xlsx')
I get the following error:
Error: NoSuchMethodError (Java): org.apache.xmlbeans.XmlOptions.setSaveAggressiveNamespaces()Lorg/apache/xmlbeans/XmlOptions;
I was in contact with Martin Studer and the problem is probably caused by multiple versions of xmlbeans.
I tried to find these using tattletale and jarfish but can only find the one version xmlbeans-2.6.0.jar.
As my java knowledge is non-existent and my R knowledge very rudimentary I need some specific help on how to solve this issue.
Other things of interest:
`java -version` --> java version "1.7.0_80"
output of sessionInfo() in R:
R version 3.2.3 (2015-12-10)
Platform: i386-w64-mingw32/i386 (32-bit)
Running under: Windows 7 x64 (build 7601) Service Pack 1
locale:
[1] LC_COLLATE=German_Germany.1252 LC_CTYPE=German_Germany.1252
[3] LC_MONETARY=German_Germany.1252 LC_NUMERIC=C
[5] LC_TIME=German_Germany.1252
attached base packages:
[1] stats graphics grDevices utils datasets methods base
loaded via a namespace (and not attached):
[1] tools_3.2.3
Output from cat(getOption("java.stacktrace")):
java.lang.NoSuchMethodError: org.apache.xmlbeans.XmlOptions.setSaveAggressiveNamespaces()Lorg/apache/xmlbeans/XmlOptions;
at org.apache.poi.POIXMLDocumentPart.<clinit>(POIXMLDocumentPart.java:62)
at org.apache.poi.ss.usermodel.WorkbookFactory.create(WorkbookFactory.java:86)
at com.miraisolutions.xlconnect.Workbook.<init>(Workbook.java:92)
at com.miraisolutions.xlconnect.Workbook.<init>(Workbook.java:99)
at com.miraisolutions.xlconnect.Workbook.getWorkbook(Workbook.java:1300)
at com.miraisolutions.xlconnect.Workbook.getWorkbook(Workbook.java:1318)
at com.miraisolutions.xlconnect.integration.r.RWorkbookWrapper.<init>(RWorkbookWrapper.java:43)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at RJavaTools.newInstance(RJavaTools.java:352)
Output from rJava::.jclassPath():
[1] "C:\\Program Files\\R\\R-3.2.3\\library\\rJava\\java"
[2] "C:\\Program Files\\R\\R-3.2.3\\library\\XLConnectJars\\java"
[3] "C:\\Program Files\\R\\R-3.2.3\\library\\XLConnectJars\\java\\ooxml-schemas-1.1.jar"
[4] "C:\\Program Files\\R\\R-3.2.3\\library\\XLConnectJars\\java\\xmlbeans-2.6.0.jar"
[5] "C:\\Program Files\\R\\R-3.2.3\\library\\XLConnect\\java"
[6] "C:\\Program Files\\R\\R-3.2.3\\library\\XLConnect\\java\\commons-codec-1.9.jar"
[7] "C:\\Program Files\\R\\R-3.2.3\\library\\XLConnect\\java\\joda-time-2.3.jar"
[8] "C:\\Program Files\\R\\R-3.2.3\\library\\XLConnect\\java\\poi-3.12-beta1.jar"
[9] "C:\\Program Files\\R\\R-3.2.3\\library\\XLConnect\\java\\poi-ooxml-3.12-beta1.jar"
[10] "C:\\Program Files\\R\\R-3.2.3\\library\\XLConnect\\java\\XLConnect-0.2-11.jar"