When you use the page base class, if the base class page is debugged at an error, open the ASPX page editor of the reference base class, the error window will pop up:
Microsfot Development Environment does not load this file in the Web Forms designer. Correct the following error and reload; the class in the file cannot be designed, so the designer cannot be displayed for the file. Designer Check out the file with the following class: AAA (opened page) Failed to load the base class "bbb.pagebase." (Reference base class) If the assembly is part of the project, make sure it has been referenced or generated.
Workaround: 1. Guarantee the base class to be correct
2. Comment of the incorrect code to the base class in the subclass
3. Rehelation, pass. Error will disappear
The reason may be that the .NET framework compiler is caused
