You have an error in file "WebService/Browse.aspx". This is Sitecore Rocks service.
As I see on your screenshot you are using Sitecore version 9.3. Parameterless constructor for LoggedInArgs was obsolete in sitecore 9 and completely removed in 9.3.
It seems that you use old version of Sitecore Rocks. Just install the latest version (or remove it at all if you dont need it and the error will disappear).
Sitecore Rocks versions 4.x are compatible with Sitecore 9.3
https://github.com/Sitecore/Sitecore.Rocks/releases
Edit #1
I downloaded and extracted Browse.aspx from latest version - it uses LoggingInArgs() without params. Looks like Sitecore Rocks bug.
![enter image description here](https://i.sstatic.net/Ypdpu.png)
Edit #2:
I installed latest version of Sitecore Rocks on my clear Sitecore 9.3 to test this issue.
![enter image description here](https://i.sstatic.net/yTkRM.png)
BUT
When I navigate to page preview in sitecore it works good:
![enter image description here](https://i.sstatic.net/PlZcI.png)
It is because Browse.aspx should not be hitted from sitecore.
This issue is reproduced only by opening browser from Sitecore Rocks in Visual Studio.
![enter image description here](https://i.sstatic.net/ZBZ0o.png)
Solution:
You can fix it manually by adding current HttpContext as a parameter.
Open sitecore\shell\WebService\Browse.aspx and add Request.RequestContext.HttpContext as a parameter in line 43:
var args2 = new Sitecore.Pipelines.LoggedIn.LoggedInArgs(Request.RequestContext.HttpContext);
It is tested and works good for me.