Failure to execute NONMEM from R

Dear NMusers, Recently I need to execute NONMEM 7.4 from Rstudio terminal. I have tried the following scripts: 1. `system2("execute FIT_01.mod")` #Through PsN, using `system2` 2. `shell("execute FIT_01.mod")` #Through PsN, using `shell` 3. `write("execute FIT_01.mod", "FIT_01.bat")` `shell("FIT_01.bat")` #Through PsN, using `shell` to call a batch file 4. `write("execute FIT_01.mod", "FIT_01.bat")` `shell.exec("FIT_01.bat")` #Through PsN, using `shell.exec` to call a batch file 5. The above commands, but call through C:/nm74g64/run/nmfe74.bat directly The above were also tested using the test dataset `CONTROL5` Results: 1. gave me the `running command '"execute FIT_01.mod"' had status 127` warning without any execution (2)-(4) gave me the following messages: Starting 1 NONMEM executions. 1 in parallel. S:1 .. All executions started. Starting NMTRAN NMtran failed. There is no output for model 1. Contents of FMSG: Not restarting this model. F:1 .. execute done (5) similar to (1) but the status/error code became 107 None of the above has led to a successful NONMEM run. But the above command lines work when outside R (i.e. through `cmd` +/- PsN) Is there anyone experiencing the same issue? System/software info: OS: Windows 10 NONMEM v7.4 R3.4.2 Rstudio v1.1.383 Best regards, Matthew Hui PhD Student School of Pharmacy Faculty of Medicine The Chinese University of Hong Kong