Stuck on "Loading MCreator Windows"

Issue description

Hello! I haven't seen any reports on this topic, and if there are, I'm sorry for being a ditto and could you send me to that tracker? Anyway, I have had an error each time I have tried to open up the program where it will get to the new main menu just fine, but not go any farther than that. It will also still be running after I close out of the program, being stuck on the "Loading MCreator Windows" screen of the loading menu. I have reinstalled it a few times, but it does not seem to be fixing the program. 

Here's the report from the .bat file:

2019-07-31-22:01:26 [main/INFO] [Launcher] Starting MCreator 1.9.0, full version: 1.9.0
2019-07-31-22:01:26 [main/INFO] [Launcher] Java version: 1.8.0_212, specification: 1.8, VM name: LibericaJDK 64-Bit Server VM
2019-07-31-22:01:26 [main/INFO] [Launcher] Current JAVA_HOME for running instance: C:\Program Files\Pylo\MCreator\jdk\jre
2019-07-31-22:01:26 [main/INFO] [Launcher] Installation path: C:\Program Files\Pylo\MCreator
2019-07-31-22:01:26 [main/INFO] [Launcher] User home of MCreator: C:\Users\costco\.mcreator\
2019-07-31-22:01:28 [AWT-EventQueue-0/INFO] [Application] Generators loaded: [1.12.2]
2019-07-31-22:01:29 [AWT-EventQueue-0/INFO] [UpdateNotify] Skipping update message ...
2019-07-31-22:01:29 [AWT-EventQueue-0/ERROR] [Exception] Uncaught exception in AWT-EventQueue-0
java.lang.NullPointerException: null
        at net.mcreator.ui.WorkspaceSelector.c(SourceFile:312) ~[mcreator.jar:?]
        at net.mcreator.ui.WorkspaceSelector.setVisible(SourceFile:360) ~[mcreator.jar:?]
        at net.mcreator.ui.g.f(SourceFile:190) ~[mcreator.jar:?]
        at net.mcreator.ui.g.<init>(SourceFile:133) ~[mcreator.jar:?]
        at net.mcreator.ui.g.b(SourceFile:159) ~[mcreator.jar:?]
        at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311) ~[?:1.8.0_212]
        at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758) ~[?:1.8.0_212]
        at java.awt.EventQueue.access$500(EventQueue.java:97) ~[?:1.8.0_212]
        at java.awt.EventQueue$3.run(EventQueue.java:709) ~[?:1.8.0_212]
        at java.awt.EventQueue$3.run(EventQueue.java:703) ~[?:1.8.0_212]
        at java.security.AccessController.doPrivileged(Native Method) ~[?:1.8.0_212]
        at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:74) ~[?:1.8.0_212]
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:728) ~[?:1.8.0_212]
        at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:205) [?:1.8.0_212]
        at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116) [?:1.8.0_212]
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105) [?:1.8.0_212]
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101) [?:1.8.0_212]
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93) [?:1.8.0_212]
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:82) [?:1.8.0_212]
2019-07-31-22:01:41 [AWT-EventQueue-0/INFO] [Website API] Trying to log in user Waffle_Fluffie
2019-07-31-22:01:42 [AWT-EventQueue-0/INFO] [Website API] Checking Pylo user session
2019-07-31-22:01:42 [AWT-EventQueue-0/INFO] [Website API] Checking Pylo user session

I can choose options for opening up a new or an old workshop but it just closes if I finish setting those up, and results in the same "Loading MCreator Windows" page being there in the background after its closed. If this was fixed in 1.9.1 let me know, as I cannot find any sources for that version of the software. the last three lines are just me logging in to see if that did anything, which it did not.

Issue comments

Thank you for your extensive bug report. This is indeed a bug and we will fix it in 1.9.1.

To fix it, for now, go to this folder <user home>/.mcreator and delete file called recentworkspaces.

Then open MCreator again.