JSP scripts do not work after Plesk upgrade:
Page not found error is displayed instead of a correct page.
Java application was deployed on domain not through Plesk, so MIME types were lost in website settings during Plesk upgrade.
Corresponding MIME type should be configured in IIS manually.
IIS manager > Web Sites > domain.tld > Properties > HTTP header > MIME types > New
Configure in the following way:
MIME type: text/html