log viewer

The log-viewer is a viewer .. for logfiles.

You have to ssh to the device and delete the logfiles.

Somewhere is a documentation where to find the different logfiles.

That is actually not correct. Logviewer is a own database. It does not reflect the /log/ partition in any way. That is the reason, why the logviewer can actually show and cross relate multiple files and logs via advanced view.

Why do you want to delete the logviewer in first place? 

OK, thanks.
Learned something again.

Because the new application filter  has not been updating since 3 months in log viewer

And you can confirm / have tested that the application is really blocked?

i have tested with Skype application  an it is blocked but does not appear in application filter in log viewer

Are you also blocking the Skype websites? As a result, access may not  reach the application filter.

no the Skype websites is run However, whether it is working or not, it is assumed that it appears in application filter

The problem is: Application can break on different levels. If the Decryption is enabled, the 4th packet within a connection will be dropped. Way to soon to see something in the application filter. 

 the Decryption is  

No. That is AV. Decryption would be the points on the right or the TLS/SSL Rules on the same page. 

But again, thats only one of multiple factos, which can break your application. I would assume, you should look deeper or contact a Sophos Partner to get the configuration done. 

 the SSL/TLS is off 

 the SSL/TLS is off 

Then you have a fundamental issue within your Setup, which needs to be checked by a Sophos Partner. There seems to be something broken in your network.