Even if you have 1.5.97 perfectly set up, Steam will try to "update" it to 1.6.x. Here is your fortress wall:
Installing SKSE 1.5.97 is relatively straightforward:
: On the dashboard, click the plus (+) button, select "New," and point the "Target" to your skse64_loader.exe .
Most Wabbajack modlists (like Living Skyrim 4 or Wildlander ) require 1.5.97 automatically. The installer handles the downgrade for you.
Press Windows Key + R , type steam://open/console , and hit Enter.
If you want to run a 1,000+ mod list with custom LODs, proper crash analysis, and niche framework mods,
Some custom perk overhaul mods depend on specific early builds of CSF that never saw an AE update.