Réna,
many thanks for providing the schematic.
It is clear now that the SPI related ChipSelectN is connected to I07 and the CE to I09.
In my project the 2.4 GHz radio was working well, but the MicroSD was not.
Even without radio functionality in the code the microSD was not working anymore, when the NRFL01+ 2.4 GHz Radio Shield was connected to the bus.
This has been solved by just securing the SPI bus before
SD.begin(chipSelect)
by setting I07 (ChipSelectN of the NRF24L01+ radio) as output and making it high.
So adding the following code at the start of the setup:
pinMode(7, OUTPUT);
digitalWrite(7, HIGH);
This was sufficient to solve the problem.
Doing the same with the ChipSelectN of the microSD (I10) does not harm, but is not strictly necessary.
Regards,
Willem