What are the disadvantages of asp.net?

I don't think the question is fair as I would understand there will always be pros and cons of using a technology and that will depend and vary from project to project as well as from perspective to perspective

I don't agree with the answers given by all other members,

ASP.NET is a huge framework developed on .net framework, under this umbrella there comes asp.net web forms, asp.net mvc, asp.net web pages, asp.net web api, each and every of these have their own pros and cons, like in asp.net web forms are:

- Limited control over HTML- Large data in the view state- Leaky abstraction- Limited support for testing- Complicated Page Life cycle

Cons of Asp.net MVC- As it embraces clean html, one should be fluent in client side technologies as we as server side technologies.

Main disadvantage of ASP.NET is its dependency on IIS or Windows.

Tight coupling with Server controls, ASP.NET request pipeline also degrade the performance of the website.  

I do not agree with you

1- ASP.NET Core is free.

2- ASP.NET Core is platform independent (Windows, Linux and Mac)

3- VS Code is a good IDE for ASP.NET Development and its free.

Following are the advantages of ASP.NET.

• Web application exists in compiled form on the server so the execution speed is faster as compared to the interpreted scripts.
• ASP.NET makes development simpler and easier to maintain with an event-driven, server-side programming model.
• Being part of .Framework, it has access to all the features of .Net Framework.
• Content and program logic are separated which reduces the inconveniences of program maintenance.
• ASP.NET makes for easy deployment. There is no need to register components because the configuration information is built-in.
• To develop program logic, a developer can choose to write their code in more than 25 .Net languages including VB.Net, C#, JScript.Net etc.
• Introduction of view state helps in maintaining state of the controls automatically between the postbacks events.
• ASP.NET offers built-in security features through windows authentication or other authentication methods.
• Integrated with ADO.NET.
• Built-in caching features.

1.limited control over html

2.large data in the view state

3.limited support testing

4.complicated page life cycle

since I am one of microsoft products fans, I usually use that for my programs. in my point of view, one of the disadvantages of asp.net and iis is that they are not free like php and mysql.

Hosting of asp.net is expensive.

1.Undefined Application Architecture with lack of Separation of Concerns

2.Lack of Reusability and minimal parallel Development

1. Asp.net is restricted to Microsoft platform only I was not available for mac os (may you use the emulator for this).
2. It is slower to develop code in .net some times.
3. If you friendly with frameworks then it is good otherwise you need to face many problems.

Biggest disadvantage of asp.net is that it is restricted only on microsoft