library(ISLR)
library(MASS)
data("Weekly")
fit<-glm(Direction~Lag1+Lag2+Lag3+Lag4+Lag5+Volume,family = "binomial",data = Weekly)
summary(fit)
then it comes out this warning error information as same as the topic
Error in factorial(n) : argument "n" is missing, with no default.
I found whenever I use the function glm() and family="binomial", this error exists, if family="poisson", it's fine. Help! Thx in advance!
Try in a fresh R session. You may have a namespace conflict.
library(ISLR)
library(MASS)
data("Weekly")
fit<-glm(Direction~Lag1+Lag2+Lag3+Lag4+Lag5+Volume,family = "binomial",data = Weekly)
summary(fit)
#>
#> Call:
#> glm(formula = Direction ~ Lag1 + Lag2 + Lag3 + Lag4 + Lag5 +
#> Volume, family = "binomial", data = Weekly)
#>
#> Deviance Residuals:
#> Min 1Q Median 3Q Max
#> -1.6949 -1.2565 0.9913 1.0849 1.4579
#>
#> Coefficients:
#> Estimate Std. Error z value Pr(>|z|)
#> (Intercept) 0.26686 0.08593 3.106 0.0019 **
#> Lag1 -0.04127 0.02641 -1.563 0.1181
#> Lag2 0.05844 0.02686 2.175 0.0296 *
#> Lag3 -0.01606 0.02666 -0.602 0.5469
#> Lag4 -0.02779 0.02646 -1.050 0.2937
#> Lag5 -0.01447 0.02638 -0.549 0.5833
#> Volume -0.02274 0.03690 -0.616 0.5377
#> ---
#> Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
#>
#> (Dispersion parameter for binomial family taken to be 1)
#>
#> Null deviance: 1496.2 on 1088 degrees of freedom
#> Residual deviance: 1486.4 on 1082 degrees of freedom
#> AIC: 1500.4
#>
#> Number of Fisher Scoring iterations: 4
Created on 2020-07-24 by the reprex package (v0.3.0)
Thanks for replying, I tried but still not working. I updated both R and Rstudio and receive same results of error. 
Sorry to be unclear. I meant that you should open R or RStudio and before doing anything else ("new session"), cut and paste the code. The stats::glm function does not return this error; other packages' glm function might. That's what I meant by namespace.