Oracle12c R2 on Windows 10 starts only one of two instances. Manual start results in LRM-00109
I ran into the same problem. The database did not start with the service. First I checked the setting for the service using the Oracle Administration Assistant for Windows and configured the DB to start with the service start (by the way, I prefer the database to shut down immediately when the service is shut down).

But enabling the database to open at service start didn't solve the problem. Next I found that the folder %ORACLE_HOME%\database was read-only, and I did not succeed to clear this attribute using the properties dialog in the Windows Explorer. The attrib program showed no R flag, though...

It was not possible to start up the database as SYSDBA from sqlplus either - I got the same LRM-00109 error. So I copied the SPFILE to an INIT&lt;INSTANCE&gt;.ora file and edited it. Startup wasn't possible either, except when I used

startup open pfile='(ORACLE_HOME)\database\init(Instance).ora'


I finally changed the service from running as a virtual account to running as Local System - that works...

The Oracle version I use is 12.2.0.1 - I guess there is some problem with it.