attempting to embed a logo with an img tag (encoded base64) results in a video container for youtube added instead?

[kaiserso]

Hi,

I am just starting out with learnr, and was trying to add a logo image to my markdown. However, when I do so, it seems to also add a video tutorial frame to a nonexistent video on youtube?

This is the approach I'm taking:

htmltools::img(src = knitr::image_uri(file.path("logo-small

<img width="204" height="204" alt="Image" src="https://github.com/user-attachments/assets/8eb492ff-d550-4f1f-9633-045fabeaade3" />

.png")), 
               alt = 'course logo',
               style = 'position:absolute; top:0; right:0; width = "100px"; height = "100px"; padding:10px;')

System details

Output of sessioninfo::session_info()():

> sessioninfo::session_info()
─ Session info ─────────────────────────────────────────────────────────────────────────────────────────────────────────────────
 setting  value
 version  R version 4.4.0 (2024-04-24 ucrt)
 os       Windows 11 x64 (build 26100)
 system   x86_64, mingw32
 ui       RStudio
 language (EN)
 collate  English_United States.utf8
 ctype    English_United States.utf8
 tz       Africa/Johannesburg
 date     2025-07-05
 rstudio  2024.04.1+748 Chocolate Cosmos (desktop)
 pandoc   3.1.11 @ C:/Program Files/RStudio/resources/app/bin/quarto/bin/tools/ (via rmarkdown)
 quarto   ERROR: Unknown command "TMPDIR=C:/Users/fqm1/AppData/Local/Temp/1/RtmpmMR4SW/file3a6c68dbf9". Did you mean command "install"? @ C:\\PROGRA~1\\RStudio\\RESOUR~1\\app\\bin\\quarto\\bin\\quarto.exe

─ Packages ─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
 package     * version     date (UTC) lib source
 cli           3.6.5       2025-04-23 [2] CRAN (R 4.4.3)
 digest        0.6.37      2024-08-19 [2] CRAN (R 4.4.3)
 evaluate      1.0.4       2025-06-18 [1] CRAN (R 4.4.3)
 fastmap       1.2.0       2024-05-15 [2] CRAN (R 4.4.0)
 htmltools     0.5.8.1     2024-04-04 [2] CRAN (R 4.4.0)
 htmlwidgets   1.6.4       2023-12-06 [2] CRAN (R 4.4.0)
 httpuv        1.6.16      2025-04-16 [2] CRAN (R 4.4.3)
 jsonlite      2.0.0       2025-03-27 [2] CRAN (R 4.4.3)
 knitr         1.50        2025-03-16 [2] CRAN (R 4.4.3)
 later         1.4.2       2025-04-08 [2] CRAN (R 4.4.3)
 learnr        0.11.5.9000 2025-07-05 [1] Github (rstudio/learnr@a644d2d)
 lifecycle     1.0.4       2023-11-07 [2] CRAN (R 4.4.0)
 magrittr      2.0.3       2022-03-30 [2] CRAN (R 4.4.0)
 mime          0.13        2025-03-17 [2] CRAN (R 4.4.3)
 promises      1.3.3       2025-05-29 [1] CRAN (R 4.4.3)
 R6            2.6.1       2025-02-15 [2] CRAN (R 4.4.3)
 Rcpp          1.1.0       2025-07-02 [1] CRAN (R 4.4.3)
 rlang         1.1.6       2025-04-11 [2] CRAN (R 4.4.3)
 rmarkdown     2.29        2024-11-04 [2] CRAN (R 4.4.3)
 rprojroot     2.0.4       2023-11-05 [2] CRAN (R 4.4.0)
 rsconnect     1.5.0       2025-06-26 [1] CRAN (R 4.4.0)
 rstudioapi    0.17.1      2024-10-22 [2] CRAN (R 4.4.3)
 sessioninfo   1.2.3       2025-02-05 [2] CRAN (R 4.4.3)
 shiny         1.11.1      2025-07-03 [1] CRAN (R 4.4.3)
 withr         3.0.2       2024-10-28 [2] CRAN (R 4.4.3)
 xfun          0.52        2025-04-02 [2] CRAN (R 4.4.3)
 xtable        1.8-4       2019-04-21 [2] CRAN (R 4.4.0)
 yaml          2.3.10      2024-07-26 [2] CRAN (R 4.4.3)

 [1] C:/Users/fqm1/AppData/Local/R/win-library/4.4
 [2] C:/Users/fqm1/AppData/Local/Programs/R/R-4.4.0/library

────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
Warning message:
In system2("quarto", "-V", stdout = TRUE, env = paste0("TMPDIR=",  :
  running command '"quarto" TMPDIR=C:/Users/fqm1/AppData/Local/Temp/1/RtmpmMR4SW/file3a6c68dbf9 -V' had status 1

Here is an example app that reproduces the problem on my system:

---

title: "Tutorial: base R"
output: learnr::tutorial
runtime: shiny_prerendered

library(learnr)

knitr::opts_chunk$set(echo = FALSE)

htmltools::img(src = knitr::image_uri(file.path("logo-small.png")), 
               alt = 'course logo',
               style = 'position:absolute; top:0; right:0; width = "100px"; height = "100px"; padding:10px;')

The logo flashes on the screen and then is replaced by the youtube frame. The HTML still contains the reference to the logo, but it doesn't show. I find the behavior happens if I deploy locally or to shinapp.io. The error persists with different browsers (chrome and edge). Replacing the call to htmltools::img or to knitr::image_uri with the output of these commands also does not fix it.

I imagine there is something obvious I am doing wrong? Any help appreciated!