PowerShell: null value or missing property
Documentation: Microsoft Learn
Check lookup results and object properties before accessing a member that may be missing or null.
What it means
An expression evaluated to null and then something asked it for a member. Without strict mode a misspelled property quietly yields null, so the visible failure often lands a line or two after the real mistake. The lookup that was supposed to produce an object produced nothing.
Likely causes
- A Get-* call matched no objects and returned nothing at all
- The property name is misspelled, or it belongs to a different type than the one in the variable
- The property exists on the object but was never retrieved, as with Get-ADUser attributes outside the default set
- An index was taken from an array that turned out to be empty
- A function assigned its result to a variable on one branch instead of emitting it
Check
Run these checks before changing anything.
What these checks establish
Test for an absent result with $null on the left. An object with a missing property is a different condition from no object at all. Inspect the property names and the lookup that produced the value.
Fix
Capture the query result, then decide how zero, one or several matches should be handled. Inspect the exact object type before calling its method. Request nondefault AD attributes in the query. Use a documented strict-mode version during development when you want missing properties to fail near their source.
Verify: Test an empty lookup and a record with an empty or absent property. Each should produce the intended behavior instead of a misleading substitute value.
