Pathfinder only appears when using Maximum assistance theme.
Solution
Many Solid Edge defaults are saved under the appdata folder under your user account:
C:\Users\username\AppData\Roaming\Siemens\Solid Edge\Version 222\Customization
Rename the Customization folder to something else - oldCustomization for example - then reopen Solid Edge. The pathfinder should then display if the themes are the issue.
Notes and References
Hardware/Software Configuration
Platform: INTL64
OS: windows
OS Version: 10_1607
Product: SOLID_EDGE
Application: ASSEMBLY
Version: V221.0
Function: PATHFINDER
Ref: 001-10190015