If you manage AutoCAD or any FLEXlm-licensed engineering software, you know the Monday morning ritual: three engineers waiting for a license while the server says all seats are in use. The licenses aren't stolen — they're stuck in sessions that ended badly.
The fix lives in a text file that most CAD managers have never opened: the options file.
The problem: licenses don't return
When AutoCAD crashes (and it will), the license server sometimes doesn't receive the "check-in" signal. The session stays open on the server side, holding a license that no one is using. Multiply this across a week of heavy use and your 10-seat pool is effectively 6.
The fix: three lines in the options file
Your options file (for Autodesk, adskflex.opt; for SolidWorks, the SNL equivalent) lives next to your license file. Add:
TIMEOUTALL 3600 — reclaims every idle license after 1 hour. The user gets a warning dialog and can extend. This single directive eliminates 90% of the morning complaint.
RESERVE 2 AutoCAD USER group_lead — guarantees seats for people who can't wait. Trade-off: those licenses are invisible to everyone else, even when unused.
EXCLUDE ALL USER departed_employee — instantly removes a person's access without touching the license file. Essential during offboarding.
After editing, run lmutil lmreread to apply — no server restart needed.
The audit commands
-
lmutil lmstat -a -c @server— full status: every feature, every user, every session duration -
lmutil lmstat -c @server -f AutoCAD— one feature, current holders -
lmutil lmremove -c @server -f AutoCAD -u jsmith -h WORKSTATION01— force-release a stuck session (last resort: the user loses unsaved work)
Why vendors don't tell you this
The options file is documented in Flexera's admin guide, not on the CAD vendor's marketing page. It's the difference between a license server that runs itself and one that needs weekly babysitting. Most CAD managers inherit the default configuration and never touch it — which is exactly why the "all licenses in use" complaint persists across every office that doesn't set TIMEOUTALL.
We track licensing options across 170+ CAD tools at CADGuide.tools — including which vendors support network licensing, borrowing, and options-file configuration. Free, no signup.
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