Nothing stalls a design review faster than a SolidWorks seat that won’t check out. You’ve got a deadline, a full queue of assemblies to finish, and a license server that suddenly doesn’t want to cooperate. If you manage SolidWorks for a team of any size, you’ve probably seen this before: someone can’t launch the application, the error message is cryptic, and you’re left guessing whether the problem is the network, the license file, or the server itself.
This guide walks through how SolidWorks licensing actually works, the errors you’re most likely to run into, and the troubleshooting steps that resolve them quickly. It also covers the habits that prevent these issues from becoming a weekly occurrence.
How SolidWorks licensing works
SolidWorks offers two licensing models. A standalone license ties to a single machine through an activation transfer, which works fine for a solo user or a laptop that rarely changes hands. Most engineering teams, though, run SolidNetWork License (SNL) manager instead. SNL pools a set number of seats on a central server and hands them out to whichever workstation requests one, up to the limit your license file allows.
That pooling is the whole appeal of network licensing: you buy fewer seats than you have engineers, because not everyone needs SolidWorks open at the same moment. It’s also where most of the troubleshooting headaches start, because now you’ve got a client, a server, a network path between them, and a license file that all have to agree with each other.
SNL manager runs on FlexNet-based licensing, the same license management architecture that runs a large share of engineering software. If you’ve dealt with license files, host IDs, and activation transfers on other CAD tools, the underlying concepts here will feel familiar.
Common SolidWorks licensing errors and what causes them
A handful of errors account for most SolidWorks licensing support tickets. Here’s what they usually mean and where to start looking:
- “Cannot connect to license server.” The client can’t reach the SNL manager at all. This is almost always a network or firewall issue, not a license problem — the client and server simply aren’t talking.
- “No licenses are available” or “maximum number of users reached.” Every seat in your pool is checked out. Sometimes that’s accurate; other times it means a seat is stuck in a session that never properly closed.
- “Server node is down or not responding.” The SNL manager service has stopped, crashed, or lost contact with a redundant server in a three-server configuration.
- Activation or transfer errors. These show up when a host ID has changed (new machine, new network card) or when an activation wasn’t returned properly before a license file was reissued.
- Borrowed license failures. SolidWorks lets users borrow a seat for offline work, but a borrowed license that isn’t returned on time keeps a seat locked out of the pool until it expires.
Troubleshooting steps that actually fix these
Work through these in order before escalating to your reseller or Dassault Systèmes support. Most licensing problems resolve in one of the first three steps.
- Confirm the SNL manager service is running. On the license server, check that the SolidNetWork License Manager service is started. A service that’s stopped or set to manual start won’t hand out any seats, and it’s an easy thing to miss after a server reboot or a Windows update.
- Check the network path and firewall rules. SNL manager communicates over specific TCP ports between client and server. If a firewall update, a new subnet, or a VPN change blocked that path, clients will report a connection failure even though the server is healthy. Confirm the client can reach the server hostname or IP, and that the relevant ports are open in both directions.
- Verify the license file and host ID match the server. If you’ve replaced hardware, changed a network adapter, or migrated to a new VM, the host ID your license file was generated against may no longer match. You’ll need a reissued license file from your reseller in that case.
- Look for orphaned or stuck sessions. A workstation that crashed, lost network connectivity mid-session, or was put to sleep without closing SolidWorks properly can leave a seat checked out that nobody’s actually using. Restarting the SNL manager service typically clears these, though it will interrupt anyone with an active session at that moment, so time it carefully.
- Check your redundant server configuration, if you have one. Three-server (quorum) setups need at least two of the three servers reachable and in agreement to issue licenses. If one server is down and a second is unreachable, the pool won’t function even though the third server is fine on its own.
- Review borrow-license activity. If seats seem to be missing without an obvious cause, check whether someone borrowed a license for travel or remote work and hasn’t returned it. The borrow period has a defined return date, and until then, that seat is unavailable to everyone else.
Reducing how often this happens
Troubleshooting gets you unstuck today. A few ongoing habits cut down how often you need to troubleshoot at all.
Right-size your seat count against actual usage instead of headcount. Teams often buy SolidWorks licenses to match the number of engineers on staff, when the real constraint is how many people need the application open at the same peak hour. Usage data, not org charts, should drive that number.
Set up monitoring on your SNL manager so you find out about a stopped service or a failed server before your team does. A five-minute service outage caught early is a non-event. The same outage discovered when three engineers can’t launch SolidWorks before a client deadline is a different conversation entirely.
Build a habit around borrow-license hygiene, too. Borrowing is a genuinely useful feature for field engineers and remote work, but it works against you if borrowed seats routinely run out their full term instead of getting returned once the trip or project ends.
Where OpenLM comes in
Troubleshooting a single license server is one thing. Keeping visibility across SolidWorks alongside every other license server and license manager your engineering teams depend on — Autodesk, Bentley, Esri, and beyond — is a different scale of problem.
OpenLM gives license administrators a single, real-time view of usage, denials, and idle seats across all of it, so you catch a stuck session or an exhausted pool before it becomes a support ticket.
That’s the same visibility problem behind the 100+ engineering license managers OpenLM supports today, built for teams that can’t afford to find out about a licensing failure from an engineer who’s stuck waiting.
Frequently asked questions
Why does SolidWorks say a license is in use when no one seems to be running it?
That usually points to an orphaned session — a workstation that lost its connection, crashed, or went to sleep without releasing the license cleanly. Restarting the SolidNetWork License Manager service typically clears it, though anyone with an active session at that moment will need to reopen SolidWorks.
Do I need a redundant license server setup for SolidWorks?
It depends on how disruptive downtime would be for your team. A single-server setup is simpler to maintain, but a three-server redundant configuration keeps licenses available if one server goes down, which matters more for larger teams or ones running against tight deadlines.
