Error log reports "Missing Important Folder"

I have upgrade our installation from 9.0 to 9.1.7 on my way to the latest stable 10.0 version. After the upgrade I am receiving the error message below....

{"reqId":"KE\/+sN2bXva29N\/8GFnj","remoteAddr":"","app":"OC\\Files\\Cache\\Scanner","message":"Missing important folder \"\" in home storage!!! - home::F464B928-D997-4130-9FBF-E63A9A176D75","level":3,"time":"2017-12-27T17:45:29+00:00","method":"--","url":"--","user":"--"}
{"reqId":"KE\/+sN2bXva29N\/8GFnj","remoteAddr":"","app":"OC\\Files\\Cache\\Scanner","message":"Missing important folder \"\" in home storage!!! - home::F4777FB8-DDEE-4904-A3B6-F8E30F991531","level":3,"time":"2017-12-27T17:45:29+00:00","method":"--","url":"--","user":"--"}
{"reqId":"KE\/+sN2bXva29N\/8GFnj","remoteAddr":"","app":"OC\\Files\\Cache\\Scanner","message":"Missing important folder \"\" in home storage!!! - home::F5F35925-B2E0-4B3F-961A-77D2B420C4AE","level":3,"time":"2017-12-27T17:45:29+00:00","method":"--","url":"--","user":"--"}
{"reqId":"KE\/+sN2bXva29N\/8GFnj","remoteAddr":"","app":"OC\\Files\\Cache\\Scanner","message":"Missing important folder \"\" in home storage!!! - home::F80631CF-4787-4320-A471-2ED6C0155C6E","level":3,"time":"2017-12-27T17:45:29+00:00","method":"--","url":"--","user":"--"}
{"reqId":"KE\/+sN2bXva29N\/8GFnj","remoteAddr":"","app":"OC\\Files\\Cache\\Scanner","message":"Missing important folder \"\" in home storage!!! - home::FAE38C3A-13FC-4347-BA66-22A52C4F2620","level":3,"time":"2017-12-27T17:45:29+00:00","method":"--","url":"--","user":"--"}
{"reqId":"KE\/+sN2bXva29N\/8GFnj","remoteAddr":"","app":"OC\\Files\\Cache\\Scanner","message":"Missing important folder \"\" in home storage!!! - home::FDDBBE20-18A4-4DE7-AAB0-33130F758BC7","level":3,"time":"2017-12-27T17:45:29+00:00","method":"--","url":"--","user":"--"}
{"reqId":"KE\/+sN2bXva29N\/8GFnj","remoteAddr":"","app":"no app in context","message":"Invalidating tokens older than 2017-12-26T17:45:30+00:00","level":1,"time":"2017-12-27T17:45:30+00:00","method":"--","url":"--","user":"--"}

Is this something I need to be worried about? Thank you for your assistance.

I believe this is because the user has not performed their first login to the account. The home directory has not been created yet as the script to generate it has not yet been called upon. If I look at my data directory, it has folders for users who use the system, but not all users who appear in my 'users' list.

I had a blow-out in these error messages recently as I fixed up my Cron job runs as well as enabled LDAP, which imported many users whom may never login to ownCloud.

As such, I would not be worried, as you are more likely to find out from your users first if their home directories disappear whilst in use.

Great, thank you so much for the response. It makes sense. I have not had any complaints about missing data yet so, I think we're ok. Thank you again.