There is no alert screen at all.
So I turned on logs, and here is part of the log file.
I found out that it works if I add the following URL exclusion in the settings:
https://belote.ludissl.com*
(
http://www.ludicash.com* exclusion doesn't help)
[2015-07-21 15:09:36.288] [debug ] [aavm ] [ 508: 6808] Worker scan thread: opening objects
[2015-07-21 15:09:36.288] [debug ] [aavm_scan ] [ 508: 6808] AavmCheckFileCommonFlt server start: filename:C:\Windows\TEMP\_avast_\ws12FAE600.dat nativename:C:\Windows\TEMP\_avast_\ws12FAE600.dat dispname:https://u.heatmap.it/conf/www.ludicash.com.js
www.ludicash.com.js https://www.ludicash.com/salle-de-belote46.105.202.39 scantype:1 trigger:6 ticks:28518948
[2015-07-21 15:09:36.290] [debug ] [aavm_scan ] [ 508: 6808] AavmCheckFileCommonFlt server end: filename:C:\Windows\TEMP\_avast_\ws12FAE600.dat result:0x00000000 ticks:28518948
[2015-07-21 15:09:36.290] [debug ] [aavm ] [ 508: 6808] Worker scan thread: signaling
[2015-07-21 15:09:36.290] [debug ] [aavm_scan ] [ 508: 5452] AavmCheckFileCommonFlt client 508 end: filename:C:\Windows\TEMP\_avast_\ws12FAE600.dat result:0x00000000 ticks:28518948
[2015-07-21 15:09:38.102] [debug ] [aavm_scan ] [ 508: 6748] In AavmCheckFileDlgSpecifyProcessID
[2015-07-21 15:09:38.102] [debug ] [aavm_scan ] [ 508: 6748] AavmCheckFileCommonFlt client 508 start: filename:C:\Windows\TEMP\_avast_\ws12BE6310.dat nativename:C:\Windows\TEMP\_avast_\ws12BE6310.dat dispname:https://signalr.ludissl.com/signalr/negotiate?clientProtocol=1.5&connectionData=%5B%7B%22name%22%3A%22hubclassementcoupe%22%7D%5D&_=1437491374289 negotiate
https://www.ludicash.com/salle-de-belote83.149.102.12 scantype:1 trigger:6 ticks:28520773
[2015-07-21 15:09:38.102] [debug ] [aavm ] [ 508: 6932] Worker scan thread: opening objects
[2015-07-21 15:09:38.103] [debug ] [aavm_scan ] [ 508: 6932] AavmCheckFileCommonFlt server start: filename:C:\Windows\TEMP\_avast_\ws12BE6310.dat nativename:C:\Windows\TEMP\_avast_\ws12BE6310.dat dispname:https://signalr.ludissl.com/signalr/negotiate?clientProtocol=1.5&connectionData=%5B%7B%22name%22%3A%22hubclassementcoupe%22%7D%5D&_=1437491374289 negotiate
https://www.ludicash.com/salle-de-belote83.149.102.12 scantype:1 trigger:6 ticks:28520773
[2015-07-21 15:09:38.105] [debug ] [aavm_scan ] [ 508: 6932] AavmCheckFileCommonFlt server end: filename:C:\Windows\TEMP\_avast_\ws12BE6310.dat result:0x00000000 ticks:28520773
[2015-07-21 15:09:38.105] [debug ] [aavm ] [ 508: 6932] Worker scan thread: signaling
[2015-07-21 15:09:38.106] [debug ] [aavm_scan ] [ 508: 6748] AavmCheckFileCommonFlt client 508 end: filename:C:\Windows\TEMP\_avast_\ws12BE6310.dat result:0x00000000 ticks:28520773
[2015-07-21 15:09:40.707] [debug ] [aavm ] [ 508: 8160] In RefreshGlobalState fFullRefresh:0 fQuickRefresh:0
[2015-07-21 15:09:40.754] [debug ] [aavm ] [ 508: 8160] In AavmGetGlobalState
[2015-07-21 15:09:40.798] [info ] [aavm ] [ 508: 8160] - In AavmGetEngineHandle
[2015-07-21 15:09:43.220] [debug ] [aavm_scan ] [ 508: 6748] In AavmCheckFileDlgSpecifyProcessID
[2015-07-21 15:09:43.220] [debug ] [aavm_scan ] [ 508: 6748] AavmCheckFileCommonFlt client 508 start: filename:C:\Windows\TEMP\_avast_\ws12F41A48.dat nativename:C:\Windows\TEMP\_avast_\ws12F41A48.dat dispname:https://signalr.ludissl.com/signalr/start?transport=serverSentEvents&clientProtocol=1.5&connectionToken=RDcSh26%2BQDQsZKSKREy74Za5GujfHlQcFnNK1eNbvlfAKWKZEYpA5pu1f6RezGg9uFUtSsMvwmHg6XU%2FGMye8ciFxX7W%2FyPy6dMR8g4Votp7HPi%2FkVbEpE5M4yeLstoU&connectionData=%5B%7B%22name%22%3A%22hubclassementcoupe%22%7D%5D&_=1437491374290 start
https://www.ludicash.com/salle-de-belote83.149.102.12 scantype:1 trigger:6 ticks:28525890
[2015-07-21 15:09:43.221] [debug ] [aavm ] [ 508: 4952] Worker scan thread: opening objects
[2015-07-21 15:09:43.221] [debug ] [aavm_scan ] [ 508: 4952] AavmCheckFileCommonFlt server start: filename:C:\Windows\TEMP\_avast_\ws12F41A48.dat nativename:C:\Windows\TEMP\_avast_\ws12F41A48.dat dispname:https://signalr.ludissl.com/signalr/start?transport=serverSentEvents&clientProtocol=1.5&connectionToken=RDcSh26%2BQDQsZKSKREy74Za5GujfHlQcFnNK1eNbvlfAKWKZEYpA5pu1f6RezGg9uFUtSsMvwmHg6XU%2FGMye8ciFxX7W%2FyPy6dMR8g4Votp7HPi%2FkVbEpE5M4yeLstoU&connectionData=%5B%7B%22name%22%3A%22hubclassementcoupe%22%7D%5D&_=1437491374290 start
https://www.ludicash.com/salle-de-belote83.149.102.12 scantype:1 trigger:6 ticks:28525890
[2015-07-21 15:09:43.223] [debug ] [aavm_scan ] [ 508: 4952] AavmCheckFileCommonFlt server end: filename:C:\Windows\TEMP\_avast_\ws12F41A48.dat result:0x00000000 ticks:28525890
[2015-07-21 15:09:43.223] [debug ] [aavm ] [ 508: 4952] Worker scan thread: signaling
[2015-07-21 15:09:43.223] [debug ] [aavm_scan ] [ 508: 6748] AavmCheckFileCommonFlt client 508 end: filename:C:\Windows\TEMP\_avast_\ws12F41A48.dat result:0x00000000 ticks:28525890
[2015-07-21 15:09:43.421] [debug ] [aavm_scan ] [ 508: 6748] In AavmCheckFileDlgSpecifyProcessID
[2015-07-21 15:09:43.422] [debug ] [aavm_scan ] [ 508: 6748] AavmCheckFileCommonFlt client 508 start: filename:C:\Windows\TEMP\_avast_\ws12FD8748.dat nativename:C:\Windows\TEMP\_avast_\ws12FD8748.dat dispname:https://belote.ludissl.com/socket.io/1/?t=1437491383239
https://www.ludicash.com/salle-de-belote83.149.102.4 scantype:1 trigger:6 ticks:28526093
[2015-07-21 15:09:43.422] [debug ] [aavm ] [ 508: 7504] Worker scan thread: opening objects
[2015-07-21 15:09:43.422] [debug ] [aavm_scan ] [ 508: 7504] AavmCheckFileCommonFlt server start: filename:C:\Windows\TEMP\_avast_\ws12FD8748.dat nativename:C:\Windows\TEMP\_avast_\ws12FD8748.dat dispname:https://belote.ludissl.com/socket.io/1/?t=1437491383239
https://www.ludicash.com/salle-de-belote83.149.102.4 scantype:1 trigger:6 ticks:28526093
[2015-07-21 15:09:43.425] [debug ] [aavm_scan ] [ 508: 7504] AavmCheckFileCommonFlt server end: filename:C:\Windows\TEMP\_avast_\ws12FD8748.dat result:0x00000000 ticks:28526093
[2015-07-21 15:09:43.425] [debug ] [aavm ] [ 508: 7504] Worker scan thread: signaling
[2015-07-21 15:09:43.426] [debug ] [aavm_scan ] [ 508: 6748] AavmCheckFileCommonFlt client 508 end: filename:C:\Windows\TEMP\_avast_\ws12FD8748.dat result:0x00000000 ticks:28526093
[2015-07-21 15:09:50.490] [info ] [aavm ] [ 508: 6496] - In AavmGetEngineHandle
[2015-07-21 15:10:01.132] [info ] [aavm ] [ 508: 8160] - In AavmGetEngineHandle