Warning: Error in file: cannot open the connection

We are experiencing this error recurrently, and the only message that appears in the logs is the following:

“Warning: Error in file: cannot open the connection”

We have an application running on Kubernetes, deploying ShinyProxy. The error occurs when users start using the application and it throws an error. In the Kubernetes pod logs, the only message we see is the one in the title, “Warning: Error in file: cannot open the connection.” The application is inaccessible until the pod finishes, and then, if a new pod is created, it starts working fine.

One of the things we observed is that memory starts to grow, but it doesn’t reach the limits we have set in Kubernetes.
I found similar errors but I am not sure if it’s the same.
Any idea why this happens, and how I could avoid it?