The Site URL property of the project does not contain a valid URL.To ensure that designers work as expected,set the Site URL property of the project t

Some times after opening the solution file,if you search any text you will get an error as below

To fix this error see the file which has cylinder symbol as below.



Just click on that file and press F4 key,you will get a window as below on right side



Enter any site URL.Now search any text now it won't throw any error.Good Luck