I have a strange problem in Visual Studio. Today, he decided to add green wiggly characters to my code in aspx files:

I tried to remove part of the code that I wrote today, hoping to find something that disables the IDE, but I cannot solve it.
Everything compiles and works fine. When I hover over any of the underscores, I get the following message: "This name contains uppercase letters that are not allowed."
I have it on all my content pages.
Has anyone seen this before or can suggest how to decide what might be wrong?
And by the way, the code passes the W3C check
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