Problems with shiny app after R upgrade on Centos 6.9



We have a shiny app that functional prior to the recent upgrade to R 3.5. Following the upgrade, and upgrading the R packages with:

update.packages(checkBuilt=TRUE, ask=FALSE)

the app seems to be completely functional on our server running Centos 7 (see here).

However, similar applications running on our private development server, running Centos 6.9, are not working properly. Specifically, the various elements from ui.R are rendered to the page, but the formatting is wrong (see attached image) and the data tables and plots returned by the app are not accessible. For example clicking on the "Brief", "Data", or "Plot" links do nothing except add "#tab-9453-5" to the end of the url. The log only shows the following:

Listening on

Execution halted

The server that is working is running Centos 7.5 and Shiny Server v1.0.0.42 (Node.js v0.10.21). The other server is back at Centos 6.9 and Shiny Server v1.5.6.875 (Node.js v6.10.3).

Any suggestions about what to check on the development server to address this problem would be greatly appreciated. Eventually, we'll upgrade that machine to 7.5, but for now, we're stuck at 6.9 and I'd like to have these applications working.