导致Template.merge（）失败的原因是什么？如何避免它？

Our team has been experiencing a recurring problem with velocity templates. Upon rendering, some throw a RuntimeException with the message "Template.merge() failure - Unable to render Velocity Template, '/template.vm'". We have not been able to reproduce the problem and the documentation on the web is pretty insufficient. The problem is not consistently reproducible - the same templates whose rendering sometimes causes the error also manage to display without problems at other times. The Template class Our team has been experiencing a recurring prob