# Cmdstanr fails to read its own csv files for large number of parameters

**URL:** <https://discourse.mc-stan.org/t/cmdstanr-fails-to-read-its-own-csv-files-for-large-number-of-parameters/22450>\
**Category:** CmdStan\
**Tags:** cmdstanr\
**Created:** [May 12, 2021, 8:13pm UTC](https://discourse.mc-stan.org/t/cmdstanr-fails-to-read-its-own-csv-files-for-large-number-of-parameters/22450 "2021-05-12T20:13:38Z")\
**Posts on this page:** 2\
**Page:** 2

<div class="post-metadata">

**Author:** ![DominiqueMakowski](https://yyz2.discourse-cdn.com/flex030/user_avatar/discourse.mc-stan.org/dominiquemakowski/32/2315_2.png) [@DominiqueMakowski](https://discourse.mc-stan.org/u/DominiqueMakowski)\
**Post date:** [August 9, 2022, 4:07am UTC](https://discourse.mc-stan.org/t/cmdstanr-fails-to-read-its-own-csv-files-for-large-number-of-parameters/22450/21 "2022-08-09T04:07:00Z")

</div>

Strangely, I have the same issue on one of my (smaller) laptop, but not with large data (90k observations, bernoulli mixed model, cmdstanr backend)… despite updating all from latest GitHub. Any thoughts?

```nohighlight
Compiling Stan program...
Start sampling
Running MCMC with 4 parallel chains...

Warning: Chain 1 finished unexpectedly!

Warning: Chain 2 finished unexpectedly!

Warning: Chain 3 finished unexpectedly!

Warning: Chain 4 finished unexpectedly!

Warning: Use read_cmdstan_csv() to read the results of the failed chains.
Error in cmdstanr::read_cmdstan_csv(out$output_files(), variables = "", : 
  Assertion on 'files' failed: No file provided.
In addition: Warning messages:
1: All chains finished unexpectedly! Use the $output(chain_id) method for more information.
 
2: No chains finished successfully. Unable to retrieve the fit. 

```

```nohighlight
R version 4.2.0 (2022-04-22 ucrt)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 10 x64 (build 19042)

Matrix products: default

locale:
[1] LC_COLLATE=English_Singapore.utf8 LC_CTYPE=English_Singapore.utf8   
[3] LC_MONETARY=English_Singapore.utf8 LC_NUMERIC=C                      
[5] LC_TIME=English_Singapore.utf8    

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

other attached packages:
[1] brms_2.17.5 Rcpp_1.0.8.3 cmdstanr_0.5.3

loaded via a namespace (and not attached):
 [1] Brobdingnag_1.2-8 jsonlite_1.8.0 gtools_3.9.3        
 [4] StanHeaders_2.21.0-7 RcppParallel_5.1.5 threejs_0.3.3       
 [7] shiny_1.7.2 assertthat_0.2.1 posterior_1.2.2     
[10] distributional_0.3.0 stats4_4.2.0 tensorA_0.36.2      
[13] pillar_1.8.0 backports_1.4.1 lattice_0.20-45     
[16] glue_1.6.2 digest_0.6.29 promises_1.2.0.1    
[19] checkmate_2.1.0 colorspace_2.0-3 htmltools_0.5.2     
[22] httpuv_1.6.5 Matrix_1.4-1 plyr_1.8.7          
[25] dygraphs_1.1.1.6 pkgconfig_2.0.3 rstan_2.21.5        
[28] purrr_0.3.4 xtable_1.8-4 mvtnorm_1.1-3       
[31] scales_1.2.0 processx_3.7.0 later_1.3.0         
[34] tibble_3.1.8 bayesplot_1.9.0 generics_0.1.3      
[37] farver_2.1.1 ggplot2_3.3.6 ellipsis_0.3.2      
[40] DT_0.23 shinyjs_2.1.0 cli_3.3.0           
[43] crayon_1.5.1 magrittr_2.0.3 mime_0.12           
[46] ps_1.7.1 fansi_1.0.3 nlme_3.1-157        
[49] xts_0.12.1 pkgbuild_1.3.1 colourpicker_1.1.1  
[52] prettyunits_1.1.1 tools_4.2.0 loo_2.5.1           
[55] lifecycle_1.0.1 matrixStats_0.62.0 stringr_1.4.0       
[58] munsell_0.5.0 callr_3.7.0 compiler_4.2.0      
[61] rlang_1.0.4 grid_4.2.0 ggridges_0.5.3      
[64] rstudioapi_0.13 htmlwidgets_1.5.4 crosstalk_1.2.0     
[67] igraph_1.3.1 miniUI_0.1.1.1 base64enc_0.1-3     
[70] codetools_0.2-18 gtable_0.3.0 inline_0.3.19       
[73] abind_1.4-5 DBI_1.1.2 markdown_1.1        
[76] reshape2_1.4.4 R6_2.5.1 gridExtra_2.3       
[79] rstantools_2.2.0 zoo_1.8-10 knitr_1.39          
[82] bridgesampling_1.1-2 dplyr_1.0.9 fastmap_1.1.0       
[85] utf8_1.2.2 shinythemes_1.2.0 shinystan_2.6.0     
[88] stringi_1.7.6 parallel_4.2.0 vctrs_0.4.1         
[91] tidyselect_1.1.2 xfun_0.31 coda_0.19-4  

```

---

<div class="post-metadata">

**Author:** ![rok\_cesnovar](https://avatars.discourse-cdn.com/v4/letter/r/7bcc69/32.png) [@rok\_cesnovar](https://discourse.mc-stan.org/u/rok_cesnovar)\
**Post date:** [August 9, 2022, 7:00am UTC](https://discourse.mc-stan.org/t/cmdstanr-fails-to-read-its-own-csv-files-for-large-number-of-parameters/22450/22 "2022-08-09T07:00:41Z")

</div>

This is a different issue, as your chains have failed for some reason. Please open a separate thread if the issue persists.

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