NPE on activation of SlingServletResolver

The following happens when SCR is restarted:
This might be a timing issue as the reference gets stale while the resolver is activating, or for some reason the stale reference did not get removed from the list

24.11.2017 15:49:21.348 ERROR [pool-4-thread-1] org.apache.sling.servlets.resolver bundle org.apache.sling.servlets.resolver:2.4.14 (538)[org.apache.sling.servlets.resolver.SlingServletResolver(3037)] : The activate method has thrown an exception (java.lang.NullPointerException)
java.lang.NullPointerException: null
at org.apache.sling.servlets.resolver.internal.SlingServletResolver.createServlet(SlingServletResolver.java:1010)
at org.apache.sling.servlets.resolver.internal.SlingServletResolver.createAllServlets(SlingServletResolver.java:982)
at org.apache.sling.servlets.resolver.internal.SlingServletResolver.activate(SlingServletResolver.java:819)