Error while diff two files

The full traceback is:
Traceback (most recent call last):
File "/home/vik/.ansible/tmp/ansible-tmp-1552865637.1434965-8627458176773/AnsiballZ_difference.py", line 114, in
_ansiballz_main()
File "/home/vik/.ansible/tmp/ansible-tmp-1552865637.1434965-8627458176773/AnsiballZ_difference.py", line 106, in _ansiballz_main
invoke_module(zipped_mod, temp_path, ANSIBALLZ_PARAMS)
File "/home/vik/.ansible/tmp/ansible-tmp-1552865637.1434965-8627458176773/AnsiballZ_difference.py", line 49, in invoke_module
imp.load_module('__main__', mod, module, MOD_DESC)
File "/usr/lib/python3.6/imp.py", line 235, in load_module
return load_source(name, filename, file)
File "/usr/lib/python3.6/imp.py", line 170, in load_source
module = _exec(spec, sys.modules[name])
File "", line 618, in _exec
File "", line 678, in exec_module
File "", line 219, in _call_with_frames_removed
File "/tmp/ansible_difference_payload__2_x8wp3/__main__.py", line 385, in
File "/tmp/ansible_difference_payload__2_x8wp3/__main__.py", line 359, in main
File "/tmp/ansible_difference_payload__2_x8wp3/__main__.py", line 259, in retrieve_input
AttributeError: 'str' object has no attribute 'decode'
fatal: [localhost]: FAILED! => {
"changed": false,
"module_stderr": "Traceback (most recent call last):\n File \"/home/vik/.ansible/tmp/ansible-tmp-1552865637.1434965-8627458176773/AnsiballZ_difference.py\", line 114, in \n _ansiballz_main()\n File \"/home/vik/.ansible/tmp/ansible-tmp-1552865637.1434965-8627458176773/AnsiballZ_difference.py\", line 106, in _ansiballz_main\n invoke_module(zipped_mod, temp_path, ANSIBALLZ_PARAMS)\n File \"/home/vik/.ansible/tmp/ansible-tmp-1552865637.1434965-8627458176773/AnsiballZ_difference.py\", line 49, in invoke_module\n imp.load_module('__main__', mod, module, MOD_DESC)\n File \"/usr/lib/python3.6/imp.py\", line 235, in load_module\n return load_source(name, filename, file)\n File \"/usr/lib/python3.6/imp.py\", line 170, in load_source\n module = _exec(spec, sys.modules[name])\n File \"\", line 618, in _exec\n File \"\", line 678, in exec_module\n File \"\", line 219, in _call_with_frames_removed\n File \"/tmp/ansible_difference_payload__2_x8wp3/__main__.py\", line 385, in \n File \"/tmp/ansible_difference_payload__2_x8wp3/__main__.py\", line 359, in main\n File \"/tmp/ansible_difference_payload__2_x8wp3/__main__.py\", line 259, in retrieve_input\nAttributeError: 'str' object has no attribute 'decode'\n",
"module_stdout": "",
"msg": "MODULE FAILURE\nSee stdout/stderr for the exact error",
"rc": 1
}

PLAY RECAP *********************************************************************
localhost : ok=0 changed=0 unreachable=0 failed=1 skipped=0 rescued=0 ignored=0

Also, ansible pushed me to rename diff to difference.

- name: Diff two files
difference:
source: /home/vik/PycharmProjects/ansible/test_backup_manual/test_diff.txt
target: /home/vik/PycharmProjects/ansible/test_backup_manual/test_diff2.txt
source_type: file
target_type: file
diff: raw
register: something
- debug:
msg: "{{something}}"