package or namespace load failure - r

Question

I don't know what happened but this NAMESPACE LOAD FAILURE is coming every time I call the forecast package.
So I have used this line of code
install.packages("forecast",repos = c("http://rstudio.org/_packages",
"http://cran.rstudio.com"))
This was the console message that I got after running this code
Installing package into ‘C:/Users/adarsh/Documents/R/win-library/3.5’
(as ‘lib’ is unspecified)
Warning in install.packages :
unable to access index for repository
http://rstudio.org/_packages/bin/windows/contrib/3.5:
cannot open URL
'http://rstudio.org/_packages/bin/windows/contrib/3.5/PACKAGES'
There is a binary version available but the
source version is later:
binary source needs_compilation
forecast 8.6 8.7 TRUE
Binaries will be installed
trying URL
'http://cran.rstudio.com/bin/windows/contrib/3.5/forecast_8.6.zip'
Content type 'application/zip' length 2345112 bytes (2.2 MB)
downloaded 2.2 MB
package ‘forecast’ successfully unpacked and MD5 sums checked
The downloaded binary packages are in
C:\Users\adarsh\AppData\Local\Temp\RtmpQ58pju\downloaded_packages
I checked whether this was also the case with other packages.
install.packages("tseries")
Installing package into ‘C:/Users/adarsh/Documents/R/win-library/3.5’
(as ‘lib’ is unspecified)
Warning in install.packages :
dependency ‘quadprog’ is not available
trying URL 'https://cran.rstudio.com/bin/windows/contrib/3.5/tseries_0.10-46.zip'
Content type 'application/zip' length 414767 bytes (405 KB)
downloaded 405 KB
package ‘tseries’ successfully unpacked and MD5 sums checked**
**The downloaded binary packages are in
C:\Users\adarsh\AppData\Local\Temp\RtmpQ1vu1H\downloaded_packages**
library(tseries)
Error: package or namespace load failed for ‘tseries’ in loadNamespace(j <- i[[1L]], c(lib.loc, .libPaths()), versionCheck = vI[[j]]):
there is no package called ‘quadprog’
In addition: Warning message:
package ‘tseries’ was built under R version 3.5.3
Same error happened again. Please anyone help me.

Answer 1

I downloaded the " quadprog " package from the cran repository and saved it as zip file at C://Users/yourname/Documents/package_file.zip .
Then used the option Package Archive File (.zip; .tar.gz) in R studio and installed the above package.
Thank you