If you have access to an old installation of Autodesk Land Desktop, check the C:\Program Files\Autodesk\...\Fonts folder. How to Install PSLX Fonts in AutoCAD
Symbols (like North arrows or utility markers) appearing as question marks. Text appearing in a default, ugly "Simplex" style. Misaligned labels and broken line types. Where to Find PSLX Font Links pslx text font link
By default, this is usually: C:\Program Files\Autodesk\AutoCAD [Version]\Fonts If you have access to an old installation
The most reliable way to get the font is to ask the person who sent you the drawing to "eTransmit" the file. This bundles the drawing with all necessary SHX and PSLX font files. Misaligned labels and broken line types
The "PSLX" prefix usually refers to oint S pecial L ine e X tension fonts. These are specialized shape files (.shx) used primarily by civil engineers and surveyors to display custom symbols, line types, and technical annotations that standard Windows fonts can’t replicate. Why You Need a PSLX Font Link
Move the pslx.shx (or similarly named) file into this folder. Restart AutoCAD: The software scans this folder on startup.