One of the strange thing about supporting Arnold at Autodesk is that you have to be a guru-level licensing expert on Autodesk licensing (not RLM, but Autodesk licensing).

In this case, Maya 2019 would silently fail at startup. Sometimes you’d see the splash screen, but then that would just disappear.

• There was nothing in the Adlm.log

• No MayaAdlm log was created

• The MayaCLM log had only this:

  ERROR: checkoutLicense: Failed to authorize license

• The clm log did have this:

  JsProductLicenseFact.loadSelectedProductInfoKey - Unable to get selected product key due to unknown problem.

TIP All these log files are in the Temp folder.

• On Windows, look in %LOCALAPPDATA%\Autodesk\Logs
• On OSX, look in $TMPDIR
• On Linux, look in /var/tmp

Process Monitor confirmed that the ProductInformation.pit file was missing:

ProductInformation.pit is an all-important file used by the licensing infrastructure. Every Autodesk product must be registered in that pit file.

If ProductInformation.pit is missing, or corrupted, then everything stops working.