SECURELOAD and TRUSTEDPATHS for AutoLISP Plotting Scripts
Configure trusted AutoLISP locations without weakening AutoCAD security just to make plotting scripts easier to load.
Main idea: Solve loading problems by managing trusted locations, not by training users to bypass security warnings.
Best use: Teams that share LSP files, PC3 files, CTB/STB tables and other plotting standards.
Start with the manual workflow
Before automation, decide who owns the master routine folder and how updates are distributed. Security settings are part of deployment, not an afterthought.
Before automating a production workflow, review Load Autolisp Plotting Routines Appload, AutoLISP Plotting & PDF Automation, and CAD Plotting Downloads.
Build the automation in small layers
Step 1 — Choose the approved code folder
Where: Office CAD standards location
Do this: Use a dedicated folder for reviewed LSP files.
Check: Users know which folder contains the official version.
Step 2 — Check secure loading behavior
Where: OPTIONS / system variables
Do this: Review SECURELOAD and current TRUSTEDPATHS.
Check: You understand why an approved or unapproved file is accepted or rejected.
Step 3 — Add only the required folder
Where: Trusted Locations
Do this: Add the controlled code location rather than broad drives or download folders.
Check: The trusted scope stays narrow.
Step 4 — Load one routine
Where: APPLOAD
Do this: Load a known routine from the approved folder.
Check: It loads without an avoidable security failure.
Step 5 — Document deployment
Where: CAD standards documentation
Do this: Record the path, ownership and update procedure.
Check: A replacement workstation can be configured consistently.
A practical office folder structure
A small team can keep approved routines in a folder such as CAD-Standards/AutoLISP/Production and experimental code in a separate CAD-Standards/AutoLISP/Test folder. Only the production location should normally be trusted for all users. That simple separation prevents a downloaded test routine from quietly becoming an office standard.
If the production folder is on a network share, also plan for the day the share is temporarily unavailable. Startup routines should fail cleanly, and essential plotting should not depend on an unreliable path that makes every drawing slow to open.
What the code should control
- SECURELOAD
- TRUSTEDPATHS
- Support File Search Path
- APPLOAD Startup Suite
- Version-controlled shared code
What you should deliberately leave manual at first
Do not automatically trust Downloads, entire network drives or user home folders just because one script is convenient.
Failure modes to design for
- Different workstations point to different copies of the same LSP.
- A network path disappears and startup becomes slow or noisy.
- Users disable secure loading instead of fixing the path.
- Downloaded code is mixed with approved production code.
When this becomes a production tool
Treat plotting automation like any other CAD standard: controlled location, version number, owner, test procedure and rollback copy.
Official Autodesk references
Frequently asked questions
Should I set SECURELOAD to 0?
That is not the recommended deployment strategy. Put reviewed code in an approved trusted location instead.
Can TRUSTEDPATHS point to a network share?
It can be part of an office strategy, but the share must be stable and access-controlled. Test startup behavior when the network is unavailable.
Does TRUSTEDPATHS also replace Support File Search Path?
No. They solve different problems: one is trust/security, while support paths help AutoCAD find files.
Explore more in AutoLISP Plotting & PDF Automation.