Following warning message was received by me while installing XCMS

Warning message:

In fun(libname, pkgname) :
  mzR has been built against a different Rcpp version (0.12.7)
than is installed on your system (0.12.8). This might lead to errors
when loading mzR. If you encounter such issues, please send a report,
including the output of sessionInfo() to the Bioc support forum at 
https://support.bioconductor.org/. For details see also
https://github.com/sneumann/mzR/wiki/mzR-Rcpp-compiler-linker-issue.
 

Please help me to sort this out.

Dipali

Seems you updated the Rcpp package - now you should update/re-install the mzR package:

library(BiocInstaller)
biocLite("mzR")

Each time Rcpp is updated you should also mzR as it is compiled using Rcpp. After re-installing mzR all should work again without warnings.

cheers, jo