• When I try to register a COM class from R, I get an error about not being able to open the key CLSID. What's the problem?
    This occurs when R tries to add the class identifier to the Windows registry but does not have permission to write in the registry. You need to have the appropriate privileges.
  • When I try to create a COM object in R from a client application (e.g. Perl, Python,...), I get error messages about missing DLLs. What this?
    You need to have the directory $R_HOME/bin in your path so that the system can find the file R.dll. R_HOME is the location where R was installed. Add this to your path in the appropriate manner for your environment, e.g. by right clicking on the My Computer icon and selecting its Properties entry and then the Advanced tab; if you are using a Unix-like shell (e.g. bash or tcsh), set the path there, e.g. export PATH=$R_HOME/bin:$PATH or set path= ($path $R_HOME/bin)
  • When I run an client that tries to create a COM object from R, I get the error message 
    Error: R.DLL version does not match
    Do you know what the problem is?
    Yes, it is that system is finding a version of R.dll in your path that does not correspond to the version of R_HOME that is used to find the R packages. When we load the R.dll, that is found in your path. When we find the R packages, we look either at the value of the R_HOME environment variable, or we look in the registry to see if R_HOME has been registered. The path and the location of R_HOME should agree.