Thanks. Keeping only the first part of the sketch solves indeed the problems. When I run the sketch on the phone I can easily find the the txt file which is located on the SD external storage /games/data/test.txt but I cannot select the file (it is greyed).
on the sketch console the following message is generated
Bms paths: /storage/emulated/0 /data/user/0/processing.test.test_paul02/files /data/user/0/processing.test.test_paul02/files/data
WRITE_EXTERNAL_STORAGE
marc