A potentially dangerous Request.Form value was detected from the client (edit)

• XSS (Cross-site scripting)
• [AllowHtml]
• [ValidateInput(false)]
• requestValidationMode & validateRequest

Problem:

https://docs.microsoft.com/en-us/aspnet/whitepapers/request-validation

Solution: 

https://www.ryadel.com/en/potentially-dangerous-request-form-value-detected-client-fix/

https://www.aspsnippets.com/Articles/ASPNet-Error-A-potentially-dangerous-RequestForm-value-was-detected-from-the-client.aspx

https://www.c-sharpcorner.com/article/a-potentially-dangerous-request-form-value-was-detected-from-the-client/

https://qawithexperts.com/questions/303/a-potentially-dangerous-requestform-value-was-detected-from

https://stackoverflow.com/questions/1455528/a-potentially-dangerous-request-form-value-was-detected-from-the-client-asp-ne

https://stackoverflow.com/questions/17254354/asp-net-mvc-a-potentially-dangerous-request-form-value-was-detected-from-the-cli

Controller:

• [AllowHtml]
• [ValidateInput(false)]

Web.config:

<configuration>

  <system.web>

   <httpRuntime requestValidationMode="2.0" />

   <pages validateRequest="false" />

  </system.web>

</configuration>

<httpRuntime requestValidationMode="2.0"/>

<configuration>
    <system.web>
        <pages validateRequest="false" />
    </system.web>
</configuration>