Model file size

Hello,
I was creating some concepts programmatically and, at the end, everything became unresponsive.
Log (mpsvcs.log) shows several exceptions:
ERROR - jetbrains.mps.vcs.changesmanager.SimpleCommandQueue - java.lang.NullPointerException exception in ChangesManager command queue java.lang.NullPointerException     at jetbrains.mps.vcs.diff.ChangeSetBuilder.buildForNode(ChangeSetBuilder.java:124)     at jetbrains.mps.vcs.changesmanager.ChangesTracking$MyEventsCollector$5$4.invoke(ChangesTracking.java:527)     at jetbrains.mps.vcs.changesmanager.ChangesTracking$MyEventsCollector$5$4.invoke(ChangesTracking.java:525)     at jetbrains.mps.vcs.changesmanager.ChangesTracking.buildAndAddChanges(ChangesTracking.java:302)     at jetbrains.mps.vcs.changesmanager.ChangesTracking.access$1200(ChangesTracking.java:76)     at jetbrains.mps.vcs.changesmanager.ChangesTracking$MyEventsCollector$5.invoke(ChangesTracking.java:525)     at jetbrains.mps.vcs.changesmanager.ChangesTracking$11$2.run(ChangesTracking.java:340)     at jetbrains.mps.ide.smodel.WorkbenchModelAccess$2.run(WorkbenchModelAccess.java:118)     at com.intellij.openapi.application.impl.ApplicationImpl.runReadAction(ApplicationImpl.java:911)     at jetbrains.mps.ide.smodel.WorkbenchModelAccess.runReadAction(WorkbenchModelAccess.java:113)     at jetbrains.mps.vcs.changesmanager.ChangesTracking$11.run(ChangesTracking.java:336)     at jetbrains.mps.vcs.changesmanager.SimpleCommandQueue$MyExecutorThread.run(SimpleCommandQueue.java:86)

There's also the following warning:
WARN - jetbrains.mps.vcs.changesmanager.BaseVersionUtil - VcsException during getting base version content:   com.intellij.openapi.vcs.VcsException: Can not show contents of 'C:\repos\Proj\solutions\SDemo2\models\xpto.mps'. File size is bigger than 20.0Mb. You can relax this restriction by increasing idea.max.vcs.loaded.size.kb property in idea.properties file.     at com.intellij.openapi.vcs.impl.ContentRevisionCache.checkContentsSize(ContentRevisionCache.java:219)     at com.intellij.openapi.vcs.impl.ContentRevisionCache.checkLocalFileSize(ContentRevisionCache.java:213)     at com.intellij.openapi.vcs.impl.ContentRevisionCache.getOrLoadAsBytes(ContentRevisionCache.java:204)     at com.intellij.openapi.vcs.impl.ContentRevisionCache.getOrLoadAsString(ContentRevisionCache.java:155)     at git4idea.GitContentRevision.getContent(GitContentRevision.java:75)     at jetbrains.mps.vcs.changesmanager.BaseVersionUtil.getBaseVersionContent(BaseVersionUtil.java:68)     at jetbrains.mps.vcs.changesmanager.BaseVersionUtil.getBaseVersionModel(BaseVersionUtil.java:90)     at jetbrains.mps.vcs.changesmanager.ChangesTracking.update(ChangesTracking.java:174)     at jetbrains.mps.vcs.changesmanager.ChangesTracking.access$100(ChangesTracking.java:76)     at jetbrains.mps.vcs.changesmanager.ChangesTracking$2.run(ChangesTracking.java:143)     at jetbrains.mps.vcs.changesmanager.SimpleCommandQueue$MyExecutorThread.run(SimpleCommandQueue.java:86)

I've tried but had no results.

I normally use the "Universal XML-based format" for models, is the "Universal XML-based file-per-root format" a solution for this problem?

Sérgio Ribeiro
Portugal