It is possible to force Squish to update all the screenshots used in screenshot verification points by setting the environment variable
For example, on Windows do the following:
Then execute all the tests so that Squish will retake all the screenshots. At the end, quit Squish and start it again normally (i.e., so that there is no
SQUISH_LEARN_SCREENSHOTS environment variable set), and Squish will compare screenshots as usual — only now with updated screenshots.
This feature is designed for when an application has some significant changes to its appearance that would invalidate lots of screenshot verifications.