title: the type java.io.FilterOutputstream cannot be resolved. error
body: <p>I'm new to coding. while creating a simple class, I got this error and somehow, many of my previous java projects on Eclipse that worked fine before got the same error (and some new errors). now most of my codes have red cross on them, how can I fixed it.</p>
  <p>the type java.io.FilterOutputstream cannot be resolved. It is indirectly referenced from a required .class file; <strong>It says on the top of the driver classes</strong></p>
  <p>UPDATE:
  -I tried Project&gt; Clean... and it resolved the problem for most files, but not all of them.</p>
  <p>-I have the jdk.14 and its library installed.</p>