Shiny server disconnected from the server: The application unexpectedly exited

[jk45019975]

We have a web-based Shiny server application that is used to copy files in a virtual machine from Azure.

As a user, after visiting the application, I encounter an error in the UI showing Disconnected from Server with a reload option.

Upon further inspection in the developer tools (Microsoft Edge) on console, I can see the message:

“The application unexpectedly exited. Diagnostic information is private. Please ask your system admin for permission if you need to check the R logs.”

We have a server.R file where I have set the log level to TRACE. However, we are not able to see the root cause, or any information related to the “Disconnected from Server” issue in these logs.

I would appreciate any suggestions on how we should monitor R logs to diagnose this issue. If anyone has faced a similar issue with their Shiny app, your help would be greatly appreciated.

Thanks in advance!

[gadenbuie]

Duplicate of #4096, opened accidentally?

[jk45019975]

yes

[sanitingz]

@jk45019975 I had the same issue, my app run in docker env.
Edit /etc/shiny-server/shiny-server.conf, and add "sanitize_errors false;" , the detail error message will show in brower console. my case is miss a library.

[ndeke254]

@jk45019975 I had the same issue, my app run in docker env. Edit /etc/shiny-server/shiny-server.conf, and add "sanitize_errors false;" , the detail error message will show in brower console. my case is miss a library.

@sanitingz This was helpful! Thanks.

[Shubhamdhadag]

hello I'm also facing same issue plz help me

[ndeke254]

@Shubhamdhadag after including the "sanitize_errors false;" in you conf, inspect and check the console tab for the error. Mine was also a missing library.

[Shubhamdhadag]

Hi so i am making an dashboard using shiny . my dashboard is runnig on local R but when i open it on shiny after some sec the page crash and disconnected from server Reload comes
and i am not able to see my data also

Mon Jan 13 2025 01:55:04 GMT+0530 (India Standard Time) [INF]: Connection opened. https://shubhamdhadage.shinyapps.io/project/
shiny-server-client.min.js:1 Mon Jan 13 2025 01:55:04 GMT+0530 (India Standard Time) [DBG]: Open channel 0
shiny-server-client.min.js:1 Mon Jan 13 2025 01:55:12 GMT+0530 (India Standard Time) [DBG]: 1 message(s) discarded from buffer
shiny-server-client.min.js:1 Mon Jan 13 2025 01:55:21 GMT+0530 (India Standard Time) [DBG]: 2 message(s) discarded from buffer
shiny-server-client.min.js:1 Mon Jan 13 2025 01:55:28 GMT+0530 (India Standard Time) [INF]: Connection closed. Info: {"type":"close","bubbles":false,"cancelable":false,"timeStamp":1736713528827,"wasClean":true,"code":4702,"reason":"Error reading from Shiny"}
shiny-server-client.min.js:1 Mon Jan 13 2025 01:55:28 GMT+0530 (India Standard Time) [DBG]: SockJS connection closed
shiny-server-client.min.js:1 Mon Jan 13 2025 01:55:28 GMT+0530 (India Standard Time) [DBG]: Channel 0 is closed
shiny-server-client.min.js:1 Mon Jan 13 2025 01:55:28 GMT+0530 (India Standard Time) [DBG]: Removed channel 0, 0 left
This is my console
and below is my logs of shiny
2025-01-12T20:42:58.962751+00:00 shinyapps[13702825]: LANG: C.UTF-8
2025-01-12T20:42:58.968457+00:00 shinyapps[13702825]: Working directory: /srv/connect/apps/project
2025-01-12T20:42:58.972628+00:00 shinyapps[13702825]: Using R 4.4.2
2025-01-12T20:42:58.976871+00:00 shinyapps[13702825]: R.home(): /opt/R/4.4.2/lib/R
2025-01-12T20:42:58.981088+00:00 shinyapps[13702825]: Content will use current R environment
2025-01-12T20:42:58.985225+00:00 shinyapps[13702825]: R_LIBS: (unset)
2025-01-12T20:42:58.989376+00:00 shinyapps[13702825]: .libPaths(): /usr/lib/R, /opt/R/4.4.2/lib/R/library
2025-01-12T20:42:58.993741+00:00 shinyapps[13702825]: shiny version: 1.10.0
2025-01-12T20:42:58.997989+00:00 shinyapps[13702825]: httpuv version: 1.6.15
2025-01-12T20:42:59.002030+00:00 shinyapps[13702825]: rmarkdown version: 2.29
2025-01-12T20:42:59.006193+00:00 shinyapps[13702825]: knitr version: 1.49
2025-01-12T20:42:59.010214+00:00 shinyapps[13702825]: jsonlite version: 1.8.9
2025-01-12T20:42:59.014294+00:00 shinyapps[13702825]: RJSONIO version: (none)
2025-01-12T20:42:59.018615+00:00 shinyapps[13702825]: htmltools version: 0.5.8.1
2025-01-12T20:42:59.022833+00:00 shinyapps[13702825]: reticulate version: (none)
2025-01-12T20:42:59.027129+00:00 shinyapps[13702825]: Using pandoc: /opt/connect/ext/pandoc/2.16
2025-01-12T20:42:59.031360+00:00 shinyapps[13702825]:
2025-01-12T20:42:59.036014+00:00 shinyapps[13702825]: Starting R with process ID: '32'
2025-01-12T20:42:59.040625+00:00 shinyapps[13702825]: Shiny application starting ...
2025-01-12T20:42:59.045008+00:00 shinyapps[13702825]:
2025-01-12T20:42:59.048982+00:00 shinyapps[13702825]: Attaching package: ‘shinydashboard’
2025-01-12T20:42:59.053199+00:00 shinyapps[13702825]:
2025-01-12T20:42:59.057115+00:00 shinyapps[13702825]: The following object is masked from ‘package:graphics’:
2025-01-12T20:42:59.061126+00:00 shinyapps[13702825]:
2025-01-12T20:42:59.066183+00:00 shinyapps[13702825]: box
2025-01-12T20:42:59.070250+00:00 shinyapps[13702825]:
2025-01-12T20:42:59.074530+00:00 shinyapps[13702825]: Linking to GEOS 3.10.2, GDAL 3.4.1, PROJ 8.2.1; sf_use_s2() is TRUE
2025-01-12T20:43:01.933414+00:00 shinyapps[13702825]: Breaking News: tmap 3.x is retiring. Please test v4, e.g. with
2025-01-12T20:43:01.942847+00:00 shinyapps[13702825]: remotes::install_github('r-tmap/tmap')
2025-01-12T20:43:01.948063+00:00 shinyapps[13702825]:
2025-01-12T20:43:01.953131+00:00 shinyapps[13702825]: Attaching package: ‘dplyr’
2025-01-12T20:43:01.957511+00:00 shinyapps[13702825]:
2025-01-12T20:43:01.962013+00:00 shinyapps[13702825]: The following objects are masked from ‘package:stats’:
2025-01-12T20:43:01.966562+00:00 shinyapps[13702825]:
2025-01-12T20:43:01.970962+00:00 shinyapps[13702825]: filter, lag
2025-01-12T20:43:01.975292+00:00 shinyapps[13702825]:
2025-01-12T20:43:01.979651+00:00 shinyapps[13702825]: The following objects are masked from ‘package:base’:
2025-01-12T20:43:01.983927+00:00 shinyapps[13702825]:
2025-01-12T20:43:01.988188+00:00 shinyapps[13702825]: intersect, setdiff, setequal, union
2025-01-12T20:43:01.992648+00:00 shinyapps[13702825]:
2025-01-12T20:43:01.997128+00:00 shinyapps[13702825]: Reading layer NFHS_4_Dist_PoK_CoL_Updated_Fixed' from data source 2025-01-12T20:43:02.001479+00:00 shinyapps[13702825]: /srv/connect/apps/project/NFHS_4_Dist_PoK_CoL_Updated_Fixed.shp'
2025-01-12T20:43:02.005869+00:00 shinyapps[13702825]: using driver `ESRI Shapefile'
2025-01-12T20:43:02.934331+00:00 shinyapps[13702825]: Simple feature collection with 642 features and 4 fields
2025-01-12T20:43:02.938561+00:00 shinyapps[13702825]: Geometry type: MULTIPOLYGON
2025-01-12T20:43:02.942552+00:00 shinyapps[13702825]: Dimension: XY
2025-01-12T20:43:02.946854+00:00 shinyapps[13702825]: Bounding box: xmin: 68.16256 ymin: 6.752917 xmax: 97.39555 ymax: 37.09701
2025-01-12T20:43:02.950995+00:00 shinyapps[13702825]: Geodetic CRS: WGS 84
2025-01-12T20:43:03.933912+00:00 shinyapps[13702825]:
2025-01-12T20:43:03.938539+00:00 shinyapps[13702825]: Listening on http://127.0.0.1:39897

[jcheng5]

@Shubhamdhadag First guess is you’re hitting the RAM limit for that container and the process is being killed. Can you start by either redeploying with a small subset of the data to see if that might be the reason? Or you can increase the instance size in shinyapps settings.

[Shubhamdhadag]

Thank you. It is working with a subset of data. But my total app size is 47 MB, so why is it crashing? We are having a limit of 1 GB for free.

[gadenbuie]

@Shubhamdhadag you might find this talk helpful. It's an old talk but the concepts and tools haven't changed since it was given. https://posit.co/resources/videos/profiling/