After upgrading from 9.1 to Version 9.3.0.1. The web front end stops working and all clients get the error message displayed below to them when they try to click on anything.
Error Message: Exception 'Timeout expired. The timeout period elapsed prior to obtaining a connection from the pool. This may have occurred because all pooled connections were in use and max pool size was reached.' occurred when attempting to 'esp_get_custom_lists'.
Has anybody perhaps experienced this issue or something similar?
I have since set up a new Web Extensions server to split the load. And am currently monitoring.