Some users report below exception:
org.h2.jdbc.JdbcSQLException: The database is read only [90097-159]
     at org.h2.message.DbException.getJdbcSQLException(DbException.java:329)
     at org.h2.message.DbException.get(DbException.java:169)
     at org.h2.message.DbException.get(DbException.java:146)
     at org.h2.message.DbException.get(DbException.java:135)
     at org.h2.engine.Database.checkWritingAllowed(Database.java:1626)
     at org.h2.store.PageStore.logUndo(PageStore.java:996)
     at org.h2.index.PageDataLeaf.create(PageDataLeaf.java:92)
     at org.h2.index.PageDataIndex.getPage(PageDataIndex.java:227)
     at org.h2.index.PageDataIndex. (PageDataIndex.java:81)
     at org.h2.table.RegularTable. (RegularTable.java:92)
     at org.h2.store.PageStore.openMetaIndex(PageStore.java:1511)
     at org.h2.store.PageStore.recover(PageStore.java:1328)
     at org.h2.store.PageStore.openExisting(PageStore.java:349)
     at org.h2.store.PageStore.open(PageStore.java:273)
     at org.h2.engine.Database.getPageStore(Database.java:2049)
     at org.h2.engine.Database.open(Database.java:553)
     at org.h2.engine.Database.openDatabase(Database.java:220)
     at org.h2.engine.Database. (Database.java:215)
     at org.h2.engine.Engine.openSession(Engine.java:56)
     at org.h2.engine.Engine.openSession(Engine.java:159)
     at org.h2.engine.Engine.createSessionAndValidate(Engine.java:138)
     at org.h2.engine.Engine.createSession(Engine.java:121)
     at org.h2.engine.Engine.createSession(Engine.java:28)
     at org.h2.engine.SessionRemote.connectEmbeddedOrServer(SessionRemote.java:285)
     at org.h2.jdbc.JdbcConnection. (JdbcConnection.java:110)
     at org.h2.jdbc.JdbcConnection. (JdbcConnection.java:94)
     at org.h2.Driver.connect(Driver.java:72)
     at java.sql.DriverManager.getConnection(DriverManager.java:525)
     at java.sql.DriverManager.getConnection(DriverManager.java:171)
     at com.pmease.quickbuild.plugin.report.engine.datastore.ConnectionManager.getConnection(ConnectionManager.java:23)
     at com.pmease.quickbuild.plugin.report.engine.datastore.DbStore.getConnection(DbStore.java:344)
     at com.pmease.quickbuild.plugin.report.engine.datastore.DbStore.open(DbStore.java:305)
     at com.pmease.quickbuild.plugin.report.engine.metadata.ReportCategory.getRowsCount(ReportCategory.java:292)
     at com.pmease.quickbuild.plugin.report.engine.metadata.ReportCategory.getRowsCount(ReportCategory.java:301)
     at com.pmease.quickbuild.plugin.report.engine.renderer.unprocessed.UnProcessedRenderer.isApplicable(UnProcessedRenderer.java:51)
     at com.pmease.quickbuild.plugin.report.engine.contribution.web.CategoryBuildTab.getTabs(CategoryBuildTab.java:77)
     at com.pmease.quickbuild.web.page.build.BuildPage.onInitialize(BuildPage.java:720)
     at org.apache.wicket.Component.fireInitialize(Component.java:924)
     at org.apache.wicket.MarkupContainer.internalInitialize(MarkupContainer.java:1002)
     at org.apache.wicket.Page.internalPrepareForRender(Page.java:278)
     at org.apache.wicket.Component.render(Component.java:2280)
     at org.apache.wicket.Page.renderPage(Page.java:1035)
     at org.apache.wicket.request.handler.render.WebPageRenderer.renderPage(WebPageRenderer.java:105)
     at org.apache.wicket.request.handler.render.WebPageRenderer.respond(WebPageRenderer.java:182)

It seems like that the issue is caused by a corrupt report database.