[nhat]

here's my error:

calibre 3.36 embedded-python: True is64bit: True
Linux-3.10.0-957.1.3.el7.x86_64-x86_64-with-centos-7.6.1810-Core Linux ('64bit', 'ELF')
('Linux', '3.10.0-957.1.3.el7.x86_64', '#1 SMP Thu Nov 29 14:49:43 UTC 2018')
Python 2.7.12
Linux: ('CentOS Linux', '7.6.1810', 'Core')
Interface language: None
Successfully initialized third party plugins: KindleUnpack - The Plugin (0, 81, 5) && Kindle Collections (1, 7, 23)
USB devices on system:
[['0x1949', '0x331', '0xffff', u'Amazon', u'Fire', u'G0W0T9058405FBXE'],
['0x4f2',
'0xb2da',
'0x520',
u'Chicony Electronics Co., Ltd.',
u'Integrated Camera',
u'']]

No disabled plugins
Looking for devices of type: MTP_DEVICE
Unknown device USBDevice(busnum=1, devnum=4, vendor_id=0x1949, product_id=0x0331, bcd=0xffff, manufacturer=Amazon, product=Fire, serial=G0W0T9058405FBXE) claims to be an MTP device
MTP devices connected:
USBDevice(busnum=1, devnum=4, vendor_id=0x1949, product_id=0x0331, bcd=0xffff, manufacturer=Amazon, product=Fire, serial=G0W0T9058405FBXE)

Trying to open: USBDevice(busnum=1, devnum=4, vendor_id=0x1949, product_id=0x0331, bcd=0xffff, manufacturer=Amazon, product=Fire, serial=G0W0T9058405FBXE)
Opening device failed:
Traceback (most recent call last):
File "site-packages/calibre/devices/mtp/unix/driver.py", line 150, in debug_managed_device_detection
File "site-packages/calibre/devices/mtp/driver.py", line 126, in open
File "site-packages/calibre/devices/mtp/base.py", line 26, in synchronizer
File "site-packages/calibre/devices/mtp/unix/driver.py", line 220, in open
OpenFailed: Failed to open USBDevice(busnum=1, devnum=4, vendor_id=0x1949, product_id=0x0331, bcd=0xffff, manufacturer=Amazon, product=Fire, serial=G0W0T9058405FBXE): Error: Unable to open MTP device with busnum=1 and devnum=4, tried 1 such devices


Looking for devices of type: SMART_DEVICE_APP
All IP addresses {'lo': [{'netmask': '255.0.0.0', 'peer': '127.0.0.1', 'addr': '127.0.0.1'}], 'virbr0': [{'netmask': '255.255.255.0', 'broadcast': '192.168.122.255', 'addr': '192.168.122.1'}], 'wlp3s0': [{'netmask': '255.255.255.0', 'broadcast': '192.168.0.255', 'addr': '192.168.0.14'}]}
No device is connected

Looking for devices...

Devices possibly connected: None