If .yaml files exported from Magnolia are put in a 'bootstrap' directory - such as '/apache-tomcat/webapps/magnoliaAuthor/WEB-INF/bootstrap/author' - then adminCentral is not reachable.

When you enter the url to log in (http://localhost:8080/magnoliaAuthor/.magnolia/admincentral), then you are instead forwarded to http://localhost:8080/magnoliaAuthor/.magnolia/installer which shows a tomcat 500 error message, with the first line of "java.lang.IllegalStateException: This implementation of ModuleManagerUI is only meant to be used at startup."

Checking the catalina output - you see a message like "

UUID already exists: bed25be3-378f-4f80-9140-a7302e045732)

java.lang.RuntimeException: Error importing /Users/cz/Documents/a-projects/testing/spa-editor-pd/work/apache-tomcat/webapps/magnoliaAuthor/WEB-INF/bootstrap/common/category.tour-types.yaml: A node with this UUID already exists: bed25be3-378f-4f80-9140-a7302e045732"

But it is incorrect - that ID does not exist already.

Rather than causing Magnolia not to start, exported yaml files should be imported into JCR just as an exported xml file is.