I just spent some time figuring out what causes a file error, and discovered that when the Build Action property of a file which has a Syncfusion Grid control on it is changed from Compile to None (and the project saved), the following error comes up (when you try to open the form):
"The language for this file does not support the necessary code parsing and generation services. Please ensure the file you are opening is a member of a project and then try to open the file again."
Does anyone know why this error is coming up? I turned off the compile option on the file because some of the people opening the project don't have Essential Grid installed (causing a compile error).