The custom key 0x000000000000 has been added to the default keys
ATS 0C0C757780|02C1052130
Found Mifare Classic 1k tag
ISO/IEC 14443A (106 kbps) target:
ATQA (SENS_RES): 00 44
* UID size: double
* bit frame anticollision supported
UID (NFCID1): 04 6f 4e e2 49 67 80
SAK (SEL_RES): 08
* Not compliant with ISO/IEC 14443-4
* Not compliant with ISO/IEC 18092
Fingerprinting based on MIFARE type Identification Procedure:
* MIFARE Classic 1K
* MIFARE Plus (7 Byte UID) 2K, Security level 1
Other possible matches based on ATQA & SAK values:
Try to authenticate to all sectors with default keys...
Symbols: '.' no key found, '/' A key found, '\' B key found, 'x' both keys found
[Key: 000000000000] -> [................]
[Key: ffffffffffff] -> [................]
[Key: a0a1a2a3a4a5] -> [................]
[Key: d3f7d3f7d3f7] -> [................]
[Key: 000000000000] -> [................]
[Key: b0b1b2b3b4b5] -> [................]
[Key: 4d3a99c351dd] -> [................]
[Key: 1a982c7e459a] -> [................]
[Key: aabbccddeeff] -> [................]
[Key: 714c5c886e97] -> [................]
[Key: 587ee5f9350f] -> [................]
[Key: a0478cc39091] -> [................]
[Key: 533cb6c723f6] -> [................]
[Key: 8fd0a4f256e9] -> [................]
Sector 00 - Unknown Key A Unknown Key B
Sector 01 - Unknown Key A Unknown Key B
Sector 02 - Unknown Key A Unknown Key B
Sector 03 - Unknown Key A Unknown Key B
Sector 04 - Unknown Key A Unknown Key B
Sector 05 - Unknown Key A Unknown Key B
Sector 06 - Unknown Key A Unknown Key B
Sector 07 - Unknown Key A Unknown Key B
Sector 08 - Unknown Key A Unknown Key B
Sector 09 - Unknown Key A Unknown Key B
Sector 10 - Unknown Key A Unknown Key B
Sector 11 - Unknown Key A Unknown Key B
Sector 12 - Unknown Key A Unknown Key B
Sector 13 - Unknown Key A Unknown Key B
Sector 14 - Unknown Key A Unknown Key B
Sector 15 - Unknown Key A Unknown Key B
ERROR:
No sector encrypted with the default key has been found, exiting..```
It seems to be ignoring the specified keys file. This is on Windows: keys.txt is taken from https://raw.githubusercontent.com/flipperdevices/flipperzero-firmware/dev/assets/resources/nfc/assets/mf_classic_dict.nfc