Interesting! I suspect the problem here is that your rlang is too new for your dplyr. You seem to have wound up with a funny mishmash of tidyverse-related package versions. dplyr 0.7.4 was current back in late 2017, when rlang was at 0.1.4 and the then-current version of the tidyverse umbrella package was 1.2.0.
Looking at your installed package versions, some packages are consistent with the up-to-this-minute latest:
#> # A tibble: 6 x 3
#> package installed latest
#> <chr> <pckg_vrs> <pckg_vrs>
#> 1 rlang 0.4.0 0.4.0
#> 2 ggplot2 3.2.1 3.2.1
#> 3 tidyverse 1.2.1 1.2.1
#> 4 lubridate 1.7.4 1.7.4
#> 5 modelr 0.1.5 0.1.5
#> 6 rvest 0.3.4 0.3.4
Other packages are stuck at the versions that were current when tidyverse 1.2.0 was released
#> # A tibble: 12 x 4
#> package installed tidyverse_1_2_0 latest
#> <chr> <pckg_vrs> <pckg_vrs> <pckg_vrs>
#> 1 readxl 1.0.0 1.0.0 1.3.1
#> 2 forcats 0.2.0 0.2.0 0.4.0
#> 3 stringr 1.2.0 1.2.0 1.4.0
#> 4 dplyr 0.7.4 0.7.4 0.8.3
#> 5 purrr 0.2.4 0.2.4 0.3.2
#> 6 readr 1.1.1 1.1.1 1.3.1
#> 7 jsonlite 1.5 1.5 1.6
#> 8 cli 1.0.0 1.0.0 1.1.0
#> 9 rstudioapi 0.7 0.7 0.10
#> 10 haven 1.1.0 1.1.0 2.1.1
#> 11 xml2 1.1.1 1.1.1 1.2.2
#> 12 httr 1.3.1 1.3.1 1.4.1
And then there’s a handful of packages that are at versions somewhere in between now and the tidyverse 1.2.0 era.
#> # A tibble: 4 x 4
#> package installed tidyverse_1_2_0 latest
#> <chr> <pckg_vrs> <pckg_vrs> <pckg_vrs>
#> 1 tidyr 0.8.3 0.7.2 1.0.0
#> 2 tibble 1.4.1 1.3.4 2.1.3
#> 3 hms 0.4.0 0.3 0.5.1
#> 4 broom 0.4.3 0.4.2 0.5.2
I'm hypothesizing that your specific error above might go away if you were able to downgrade rlang back to the version that was current when dplyr was at 0.7.4 — but that would almost certainly break some of the other packages that are actually up to date (e.g., ggplot2).
rlang has been under rapid and momentous development over the last two years, and the tidyverse as a whole has been moving toward ever-greater integration with the newer rlang paradigms. So I think you'd ultimately be better off bringing all of your tidyverse packages up to date (or arguing to the powers-that-be for doing so!).