Antes estava funcionando normalmente, a partir do momento que comecei a fazer as validações começou da esse erro.
This application has no explicit mapping for /error, so you are seeing this as a fallback.
Wed Sep 30 19:19:36 BRT 2020 There was an unexpected error (type=Internal Server Error, status=500). An error happened during template parsing (template: "class path resource [templates//paginas/formulario.html]") org.thymeleaf.exceptions.TemplateInputException: An error happened during template parsing (template: "class path resource [templates//paginas/formulario.html]") at org.thymeleaf.templateparser.markup.AbstractMarkupTemplateParser.parse(AbstractMarkupTemplateParser.java:241) at org.thymeleaf.templateparser.markup.AbstractMarkupTemplateParser.parseStandalone(AbstractMarkupTemplateParser.java:100) at org.thymeleaf.engine.TemplateManager.parseAndProcess(TemplateManager.java:666) at org.thymeleaf.TemplateEngine.process(TemplateEngine.java:1098) at org.thymeleaf.TemplateEngine.process(TemplateEngine.java:1072) at org.thymeleaf.spring5.view.ThymeleafView.renderFragment(ThymeleafView.java:362) at org.thymeleaf.spring5.view.ThymeleafView.render(ThymeleafView.java:189) at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1373) at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1118) at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1057) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943) at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898) at javax.servlet.http.HttpServlet.service(HttpServlet.java:634) at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)