Android
Mount SD Card Manually auf Android
When an SD card is not mounted, Android treats the storage as unavailable even though the card is physically inserted. Apps cannot write to it, the Files app shows it as empty or missing, and photos or downloads set to save on the card will fail silently. This usually happens when the card was removed unsafely last time, or when it was inserted while the phone was busy with another storage task.
You can trigger the mount manually through the storage settings instead of restarting the phone. Open Open the Settings ➔ Tap on Storage ➔ Tap on SD card ➔ Tap on Mount. The system rechecks the file system on the card and makes it available again if no hardware fault is present.
If the option to mount is missing or greyed out, the card itself may be damaged or formatted with an unsupported file system. In that case, mounting will not help and the card needs to be checked on a computer first. A restart is only useful if the storage service itself has crashed, which is less common than a simple mount failure.