Caused by: java.nio.charset.MalformedInputException: Input length = 1

java.lang.IllegalStateException: Failed to load property source from location 'classpath:/application.yml'
    at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.loadIntoGroup(ConfigFileApplicationListener.java:476)
    at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.load(ConfigFileApplicationListener.java:465)
    at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.load(ConfigFileApplicationListener.java:386)
    at org.springframework.boot.context.config.ConfigFileApplicationListener.addPropertySources(ConfigFileApplicationListener.java:225)
    at org.springframework.boot.context.config.ConfigFileApplicationListener.postProcessEnvironment(ConfigFileApplicationListener.java:195)
    at org.springframework.boot.context.config.ConfigFileApplicationListener.onApplicationEnvironmentPreparedEvent(ConfigFileApplicationListener.java:182)
    at org.springframework.boot.context.config.ConfigFileApplicationListener.onApplicationEvent(ConfigFileApplicationListener.java:168)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:172)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:165)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:122)
    at org.springframework.boot.context.event.EventPublishingRunListener.environmentPrepared(EventPublishingRunListener.java:74)
    at org.springframework.boot.SpringApplicationRunListeners.environmentPrepared(SpringApplicationRunListeners.java:54)
    at org.springframework.boot.SpringApplication.prepareEnvironment(SpringApplication.java:325)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:296)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1118)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1107)
    at com.chinanums.schoolspayment.SchoolspaymentApplication.main(SchoolspaymentApplication.java:10)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49)
Caused by: org.yaml.snakeyaml.error.YAMLException: java.nio.charset.MalformedInputException: Input length = 1
    at org.yaml.snakeyaml.reader.StreamReader.update(StreamReader.java:254)
    at org.yaml.snakeyaml.reader.StreamReader.<init>(StreamReader.java:58)
    at org.yaml.snakeyaml.Yaml.loadAll(Yaml.java:518)
    at org.springframework.beans.factory.config.YamlProcessor.process(YamlProcessor.java:157)
    at org.springframework.beans.factory.config.YamlProcessor.process(YamlProcessor.java:135)
    at org.springframework.boot.env.YamlPropertySourceLoader$Processor.process(YamlPropertySourceLoader.java:101)
    at org.springframework.boot.env.YamlPropertySourceLoader.load(YamlPropertySourceLoader.java:58)
    at org.springframework.boot.env.PropertySourcesLoader.load(PropertySourcesLoader.java:128)
    at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.doLoadIntoGroup(ConfigFileApplicationListener.java:490)
    at org.springframework.boot.context.config.ConfigFileApplicationListener$Loader.loadIntoGroup(ConfigFileApplicationListener.java:473)
    ... 22 common frames omitted
Caused by: java.nio.charset.MalformedInputException: Input length = 1
    at java.nio.charset.CoderResult.throwException(CoderResult.java:281)
    at sun.nio.cs.StreamDecoder.implRead(StreamDecoder.java:339)
    at sun.nio.cs.StreamDecoder.read(StreamDecoder.java:178)
    at java.io.InputStreamReader.read(InputStreamReader.java:184)
    at org.yaml.snakeyaml.reader.UnicodeReader.read(UnicodeReader.java:125)
    at org.yaml.snakeyaml.reader.StreamReader.update(StreamReader.java:223)
    ... 31 common frames omitted

第一种可能是你的application.yml文件编码格式有问题，改为UTF-8，如下：

 第二种:

可能就是你的application.yml文件是通过把其他类型的文件后缀名直接改为yml生成的，这时就需要你把application.yml中的内容全部复制，然后删除，再新建一个application.yml文件，

将复制的内容拷贝进去再运行项目就不会报错了。