As of tibble_3.1.4, it looks like view() requires a manual option (tibble.view_max) in order to handle tbl_lazy objects. As a workaround, I have added this to my .Rprofile, but it would be beneficial to add this option on load.
library(tidyverse)
mf <- dbplyr::memdb_frame(g = c(1, 1, 2, 2, 2), x = 1:5, y = 5:1)
mf %>% view()
#> Error: `n` must be a non-negative integer
#> Run `rlang::last_error()` to see where the error occurred.
options(tibble.view_max=1000)
mf %>% view()
(reprex() is not returning the error, so I manually copied this in)