account is limited to
max simultaneous ngrok client session
An ngrok account is limited in how many agents it can simultaneously run. This limit is listed for each plan as "online ngrok processes" on the pricing page. This error indicates you've exceeded that limit.
The list of online ngrok processes is visible in the dashboard.
Make sure you're not accidentally leaving any unnecessary ngrok agent sessions open. Stopping any agent processes that aren't necessary frees up that resource so you can use it elsewhere in your setup.
You may think you need to use multiple agents to accomplish the goal of tunneling to multiple services, but if all of your services are reachable from a single machine then you can configure a single ngrok agent running on that machine to tunnel to multiple services within a single agent session. The ngrok agent supports running multiple tunnels using either the configuration file or the ngrok agent api.
It is possible for one agent to start multiple tunnels simultaneously. This number varies depending on which plan you've selected. See the pricing page's "tunnels / ngrok process" feature for how many tunnels you may run with one agent.
You might consider upgrading your plan to one that offers more simultaneous agent sessions.
You can purchase additional licenses by adding member(s) to your team if you need the agent to run on multiple devices or run more tunnels.
If you're having trouble resolving this error, please reach out to firstname.lastname@example.org.