"database write error. disk is full or database is corrupted"

there is a lot of disk space.
what to do?

Make sure to have 40-50 GB free space in the drive where app data will be saved or else you might get block load error.
You can change the blockchain location.
STEP #1: Open cmd and enter this command:
MkLink /J "C:\Users\%user_name%\AppData\Roaming\bytecoin" "NEW_LOCATION_PATH"
Example, you want to move to D:\bytecoin. If your %user_name% is Peter, your command is
MkLink /J "C:\Users\Peter\AppData\Roaming\bytecoin" "D:\bytecoin"
STEP #2: Check in "C:\Users\Peter\AppData\Roaming\bytecoin\". If you see "bytecoin" folder (icon same as shortcut), it means that you create successfully, when you open this folder, it will open folder in "NEW_LOCATION_PATH"
STEP #3: Move all data from old folder to new folder.
STEP #4: Run Bytecoin wallet app. It should work.
STEP #5: Delete "bytecoin" folder in "C:\Users\Peter\AppData\Roaming".
That's it.
Cannot create file when that file already exist.