Session_save_path does not exist and is not writable

[hankpppl78]

when upgrading from 1.12 to 2.2.10 i get 2 errors:
1) Session_save_path exists
The session save path variabele is not valid or the directory does not exists (translated from dutch)
2) Session_save_path is writable
Cannot write in the 'session save path' directory (translated from dutch)

i have tested with php 5.4-5.6 and php 7.0-7.2.
database is version mysql 5.

i read soms thread about this issue, but none fixed my problem.
have anybody have some suggestions?
thanks a lot!