library(labelled)
library(performance)
library(see)

var_label(mtcars$wt) <- "Weight (1000 lbs)"
var_label(mtcars$mpg) <- "Miles/(US) gallon"
mtcars$am <- labelled(mtcars$am, c("automatic" = 0, "manual" = 1))

# this variable causes the error
mtcars$mpg <- labelled(mtcars$mpg, c("21" = 21))

m <- lm(mpg ~ wt + cyl + gear + disp + am, data = mtcars)

check_model(m)

> check_model(m)
Error: `check_model()` returned following error: Can't combine `..1` <character> and `..2` <double>.
  
If the error message does not help identifying your problem, another reason why `check_model()` failed might be that models of class `lm` are not yet
  supported.

> sessionInfo()
R version 4.4.0 (2024-04-24)
Platform: aarch64-apple-darwin20
Running under: macOS Sonoma 14.5

Matrix products: default
BLAS:   /System/Library/Frameworks/Accelerate.framework/Versions/A/Frameworks/vecLib.framework/Versions/A/libBLAS.dylib 
LAPACK: /Library/Frameworks/R.framework/Versions/4.4-arm64/Resources/lib/libRlapack.dylib;  LAPACK version 3.12.0

locale:
[1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8

time zone: Europe/Berlin
tzcode source: internal

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] see_0.8.4            performance_0.11.0.9 labelled_2.13.0     

loaded via a namespace (and not attached):
 [1] vctrs_0.6.5       cli_3.6.2         rlang_1.1.3       forcats_1.0.0     haven_2.5.4       generics_0.1.3    glue_1.7.0        colorspace_2.1-0  datawizard_0.10.0
[10] hms_1.1.3         scales_1.3.0      fansi_1.0.6       grid_4.4.0        munsell_0.5.1     tibble_3.2.1      lifecycle_1.0.4   insight_0.19.11   compiler_4.4.0   
[19] dplyr_1.1.4       pkgconfig_2.0.3   rstudioapi_0.16.0 R6_2.5.1          tidyselect_1.2.1  utf8_1.2.4        pillar_1.9.0      magrittr_2.0.3    tools_4.4.0      
[28] gtable_0.3.5      bayestestR_0.13.2 ggplot2_3.5.1