How to solve the "Asp.net's most common errors" Problem in the morning!

The problem has been depressing for one afternoon. I found the method and first published the following, hoping to help you:
Add <customerrors mode = "off"/> in Web. config, and an error is returned:
"/" Application Program Server error.
--------------------------------------------------------------------------------

Analyzer Error
Note: An error occurred while analyzing the resources required to provide services to this request. Check the following detailed analysis error information and modify the source file as appropriate.

Analyzer error message: an ambiguous match is found.

Source error:

Row 1: <% @ page Language = "C #" autoeventwireup = "true" inherits = "qingzhouboy_admin_class, app_web_ijr_pzui" %>
Row 2:
Row 3: <! Doctype HTML public "-// W3C // dtd xhtml 1.0 transitional // en" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
Okay, find the culprit,Solution:
After checking that the names of the two controls on the page are the same as those defined in my CS, It will be OK if I change it!Thanks to the two people's answers, I understand that the first reference is as follows:
1)
This is really the problem, ICodeThere are two controls with the same name as the page. Although direct execution is acceptable, an error will occur after the release. After you get rid of it, you can also release it.

2)

"/" Indicates a server error in the application. --------------------------------------------------------------------------------
Analyzer error Description: An error occurred while analyzing the resources required to provide services to this request. Check the following detailed analysis error information and modify the source file as appropriate.
Analyzer error message: an ambiguous match is found.

Solution:
Check whether the control on your ASPX page has the same name (case-insensitive) ID as the class variable in your Aspx. CS.

Alas, I checked this error for a long time, because when you start it in Vs, the dev Web will distinguish between the control and the background code variables in case,
After being deployed to the IIS server, the server is case-insensitive, so the variable name is duplicated, resulting in an "ambiguous match" error.

Lessons learned: This type of error rarely occurs, because we will avoid using case-sensitive variables. This is also because
It seems that some of the other people's lives have appeared once before, but they don't care too much about it. Forget it. Remember this time, I hope someone will encounter this kind of mistake in the future.
Able to search for answers in time