Internal server stopped: Illegal seek

Hello, I can start the server and use Ubooquity for a while (sync, download, reading) all works fine. Though after some time (normally around or less than 24 hours) the server shuts unexpectedly down. From the logs the following error is shown:

20190814 17:32:27 [Scanner thread] INFO com.ubooquity.data.database.c - Found 61 empty folders
20190814 17:32:27 [Scanner thread] INFO com.ubooquity.data.database.c - Deleted empty folders from database. Looking for new ones...
20190814 17:32:27 [Scanner thread] INFO com.ubooquity.data.feeder.a - Finished scanning comics directories, populating folders content cache
20190814 17:32:27 [Scanner thread] INFO com.ubooquity.data.feeder.a - Comics folder content cache populated
20190814 17:32:27 [Scanner thread] INFO com.ubooquity.data.feeder.a - Comics statistics: [total: 1655, added or updated: 0, removed: 0]
20190814 17:32:27 [Scanner thread] INFO com.ubooquity.data.feeder.a - Books statistics: [total: 481, added or updated: 0, removed: 0]
20190814 19:43:52 [main] ERROR com.ubooquity.Ubooquity - Exiting application because of exception
java.io.IOException: Illegal seek
at java.io.FileInputStream.available0(Native Method) ~[na:1.8.0_201]
at java.io.FileInputStream.available(FileInputStream.java:306) ~[na:1.8.0_201]
at java.io.BufferedInputStream.available(BufferedInputStream.java:410) ~[na:1.8.0_201]
at com.ubooquity.Ubooquity.main(SourceFile:228) ~[Ubooquity.jar:2.1.2]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_201]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_201]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_201]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_201]
at com.ubooquity.e.a.a(SourceFile:823) [Ubooquity.jar:2.1.2]
at com.ubooquity.Launcher.main(SourceFile:10) [Ubooquity.jar:2.1.2]
20190814 19:43:53 [main] ERROR com.ubooquity.Ubooquity - Failed to display error dialog
java.lang.IllegalStateException: Toolkit not initialized
at com.sun.javafx.application.PlatformImpl.runLater(PlatformImpl.java:273) ~[jfxrt.jar:na]
at com.sun.javafx.application.PlatformImpl.runLater(PlatformImpl.java:268) ~[jfxrt.jar:na]
at javafx.application.Platform.runLater(Platform.java:83) ~[jfxrt.jar:na]
at com.ubooquity.Ubooquity.main(SourceFile:264) ~[Ubooquity.jar:2.1.2]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_201]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_201]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_201]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_201]
at com.ubooquity.e.a.a(SourceFile:823) [Ubooquity.jar:2.1.2]
at com.ubooquity.Launcher.main(SourceFile:10) [Ubooquity.jar:2.1.2]
20190814 19:43:53 [Thread-2] INFO com.ubooquity.b - Stopping internal server...
20190814 19:43:53 [Thread-4] INFO o.e.jetty.server.AbstractConnector - Stopped library@1fa89059{HTTP/1.1,[http/1.1]}{0.0.0.0:8096}
20190814 19:43:53 [Thread-2] INFO com.ubooquity.data.feeder.a - Aborting content scan...
20190814 19:43:53 [Thread-2] INFO com.ubooquity.data.feeder.a - Waiting for scanner thread to stop
20190814 19:43:53 [Thread-2] INFO com.ubooquity.data.feeder.a - Scanner thread stopped
20190814 19:43:53 [Thread-4] INFO o.e.jetty.server.AbstractConnector - Stopped admin@7ca694f8{HTTP/1.1,[http/1.1]}{0.0.0.0:8097}
20190814 19:43:53 [Thread-4] INFO o.e.j.server.handler.ContextHandler - Stopped o.e.j.s.h.ContextHandler@34666fdc{/,null,UNAVAILABLE,@library}
20190814 19:43:53 [Thread-4] INFO o.e.j.server.handler.ContextHandler - Stopped o.e.j.s.h.ContextHandler@1285185c{/,null,UNAVAILABLE,@admin}
20190814 19:43:53 [Thread-2] INFO com.ubooquity.b - Internal server stopped
20190814 19:43:53 [Thread-2] INFO com.ubooquity.Ubooquity - Ubooquity has closed.

Any advice would be helpful