Unable to Run Plaxis Calculations Due to "Invalid Material Setting"

 Hi, I am running Plaxis to obtain safety factor under Eurocode 7 DA1-C2 with HS model Undrain(A). The two different cohesion and friction angles for F2 layer and Plaxis responses are:(
1) c'=0, φ=22 - Plaxis reminded of invalid material setting and failed to run.
(2) c'=2, φ=25 - Plaxis can run calculations smoothly.

Kindly assist to advise the reasons. Thank you.