Im unable to regenerate my symbol table after upgrading. looking at the stack trace, it seem my existing table is gone completely but that shouldn't stop me from making a new one.
2018-03-14 08:32:59,271 [ 295854] INFO - ct.OfflineSymbolTableGenerator - Completed activity Loading SObject docs in 20941 ms.
2018-03-14 08:32:59,273 [ 295856] INFO - ct.OfflineSymbolTableGenerator - Starting activity Loading SObject types with 1049 steps.
2018-03-14 08:32:59,443 [ 296026] INFO - ct.OfflineSymbolTableGenerator - Completed activity Loading SObject types in 170 ms.
2018-03-14 08:32:59,457 [ 296040] INFO - ct.OfflineSymbolTableGenerator - Starting activity Clearing existing offline symbol table with 1 steps.
2018-03-14 08:32:59,457 [ 296040] INFO - ct.OfflineSymbolTableGenerator - Completed activity Clearing existing offline symbol table in 0 ms.
2018-03-14 08:32:59,478 [ 296061] WARN - .IlluminatedCloudExceptionUtil -
java.lang.NullPointerException
at com.illuminatedcloud.symtab.ApexTypeName.getKeyForm(SourceFile:59)
at com.illuminatedcloud.symtab.ApexTypeName.hashCode(SourceFile:65)
at java.util.HashMap.hash(HashMap.java:338)
at java.util.HashMap.put(HashMap.java:611)
at com.illuminatedcloud.symtab.OfflineSymbolTable.getAllTypeNames(SourceFile:1162)
at com.illuminatedcloud.symtab.OfflineSymbolTable.generateApexSourceFiles(SourceFile:2467)
at com.illuminatedcloud.symtab.OfflineSymbolTable.generateOfflineSymbolTable(SourceFile:815)
at com.illuminatedcloud.intellij.settings.project.OfflineSymbolTableGenerator$3.run(SourceFile:205)
at com.intellij.openapi.progress.impl.CoreProgressManager$TaskRunnable.run(CoreProgressManager.java:713)
at com.intellij.openapi.progress.impl.CoreProgressManager.a(CoreProgressManager.java:157)
at com.intellij.openapi.progress.impl.CoreProgressManager.a(CoreProgressManager.java:543)
at com.intellij.openapi.progress.impl.CoreProgressManager.executeProcessUnderProgress(CoreProgressManager.java:488)
at com.intellij.openapi.progress.impl.ProgressManagerImpl.executeProcessUnderProgress(ProgressManagerImpl.java:94)
at com.intellij.openapi.progress.impl.CoreProgressManager.runProcess(CoreProgressManager.java:144)
at com.intellij.openapi.progress.impl.ProgressManagerImpl$2.run(ProgressManagerImpl.java:165)
at com.intellij.openapi.application.impl.ApplicationImpl$1.run(ApplicationImpl.java:315)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
2018-03-14 08:35:10,425 [ 427008] INFO - il.indexing.FileBasedIndexImpl - Rebuild requested for index CaseInsensitiveFilenameIndex
java.lang.Throwable: Rebuilding CaseInsensitiveFilenameIndex
at com.illuminatedcloud.intellij.index.IlluminatedCloudIndexUtil.rebuildIndices(SourceFile:404)
at com.illuminatedcloud.intellij.index.IlluminatedCloudIndexUtil.rebuildIndices(SourceFile:303)
at com.illuminatedcloud.intellij.index.IlluminatedCloudIndexUtil.access$100(SourceFile:60)
at com.illuminatedcloud.intellij.index.IlluminatedCloudIndexUtil$2.run(SourceFile:465)
at com.intellij.openapi.application.TransactionGuardImpl$2.run(TransactionGuardImpl.java:315)
at com.intellij.openapi.application.impl.LaterInvocator$FlushQueue.a(LaterInvocator.java:424)
at com.intellij.openapi.application.impl.LaterInvocator$FlushQueue.run(LaterInvocator.java:407)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:762)
at java.awt.EventQueue.access$500(EventQueue.java:98)
at java.awt.EventQueue$3.run(EventQueue.java:715)
at java.awt.EventQueue$3.run(EventQueue.java:709)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:732)
at com.intellij.ide.IdeEventQueue.a(IdeEventQueue.java:822)
at com.intellij.ide.IdeEventQueue._dispatchEvent(IdeEventQueue.java:650)
at com.intellij.ide.IdeEventQueue.dispatchEvent(IdeEventQueue.java:366)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)
2018-03-14 08:35:10,453 [ 427036] INFO - il.indexing.FileBasedIndexImpl - scheduleIndexRebuild, reason: checkRebuild
2018-03-14 08:35:10,616 [ 427199] INFO - g.FileBasedIndexProjectHandler - Reindexing refreshed files: 3601 to update, calculated in 162ms
2018-03-14 08:35:15,287 [ 431870] INFO - .diagnostic.PerformanceWatcher - Reindexing refreshed files took 4671ms; general responsiveness: ok; EDT responsiveness: ok
2018-03-14 08:35:15,301 [ 431884] INFO - .diagnostic.PerformanceWatcher - Pushing properties took 14ms; general responsiveness: ok; EDT responsiveness: ok
2018-03-14 08:35:15,430 [ 432013] INFO - .diagnostic.PerformanceWatcher - Indexable file iteration took 120ms; general responsiveness: ok; EDT responsiveness: ok
2018-03-14 08:35:16,429 [ 433012] INFO - rojectCodeStyleSettingsManager - Initialized from default code style settings.
2018-03-14 08:36:07,551 [ 484134] INFO - .script.IdeScriptEngineManager - javax.script.ScriptEngineManager initialized in 345 ms