Failed to check for launcher update

[Porthos]

Here I am sincerely asking for help
When I am opening the launcher, it says:
Failed to check for launcher update (An exception occurred during a WebClient request.)

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When I hit the 'Play cRPG' button, next thing occurs:

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[19:38:02] Downloading version info
[19:38:02] An exception occurred during a WebClient request.
[19:38:02] Configuration system failed to initialize
[19:38:02] Could not load file or assembly 'System.Xml, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' or one of its dependencies. The module was expected to contain an assembly manifest.
[19:38:02]
[19:38:02] System.BadImageFormatException
[19:38:02] at System.Configuration.ExceptionUtil.WrapAsConfigException(String outerMessage, Exception e, String filename, Int32 line)
[19:38:02] at System.Configuration.BaseConfigurationRecord.Init(IInternalConfigRoot configRoot, BaseConfigurationRecord parent, String configPath, String locationSubPath)
[19:38:02] at System.Configuration.RuntimeConfigurationRecord.Create(InternalConfigRoot configRoot, IInternalConfigRecord parent, String configPath)
[19:38:02] at System.Configuration.Internal.InternalConfigRoot.GetConfigRecord(String configPath)
[19:38:02] at System.Configuration.ClientConfigurationSystem.EnsureInit(String configKey)
[19:38:02] Failed to download version info, turning system proxy on
[19:38:02] Downloading version info
[19:38:02] An exception occurred during a WebClient request.
[19:38:02] Configuration system failed to initialize
[19:38:02] Could not load file or assembly 'System.Xml, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' or one of its dependencies. The module was expected to contain an assembly manifest.
[19:38:02]
[19:38:02] System.BadImageFormatException
[19:38:02] at System.Configuration.ExceptionUtil.WrapAsConfigException(String outerMessage, Exception e, String filename, Int32 line)
[19:38:02] at System.Configuration.BaseConfigurationRecord.Init(IInternalConfigRoot configRoot, BaseConfigurationRecord parent, String configPath, String locationSubPath)
[19:38:02] at System.Configuration.RuntimeConfigurationRecord.Create(InternalConfigRoot configRoot, IInternalConfigRecord parent, String configPath)
[19:38:02] at System.Configuration.Internal.InternalConfigRoot.GetConfigRecord(String configPath)
[19:38:02] at System.Configuration.ClientConfigurationSystem.EnsureInit(String configKey)
[19:38:02] Update failed

I've checked if there anyone have a similar problem, and found this. But, unfortunately, I have not found a solution. So, I am currently playing in 'Offline' mode, but it would be cool, if someone could help me to solve this. Btw I've reinstall my operating system recently (about a week ago). It may be connected somehow with my current problem or not I don't know.

[Lemonjello]

Hey I was having a weird launch issue earlier today as well, an error box popped up but I took no screenshot. I clicked the "repair" box and told the game the launch and before I knew it I was staring at the ridiculously long loading screen    Hope this helps.