Hell-o! I'm using CNTLM 0.92.3 on xubuntu 17.10. I'm behind corporate proxy. For some time I can no longer use CNTLM - after opening a web page in firefox I get this window: Network authentication A proxy requires you to authenticate with it before you can access https://xxxxxxxxx Choose a login from the list below or close this window to manually enter the required login information. CNTLM i properly configured: cntlm -M http://wp.pl Password: Config profile 1/4... Credentials rejected Config profile...