webman,报错信息

stdout.log,经常会有这样的报错信息

Fatal error: Uncaught ErrorException: (null)(): supplied resource is not a valid stream resource in Unknown:0
Stack trace:
#0 [internal function]: {closure}(2, '(null)(): suppl...', 'Unknown', 0, NULL)
#1 {main}
  thrown in Unknown on line 0

Fatal error: Uncaught ErrorException: (null)(): supplied resource is not a valid stream resource in Unknown:0
Stack trace:
#0 [internal function]: {closure}(2, '(null)(): suppl...', 'Unknown', 0, NULL)
#1 {main}
  thrown in Unknown on line 0

Fatal error: Uncaught ErrorException: (null)(): supplied resource is not a valid stream resource in Unknown:0
Stack trace:
#0 [internal function]: {closure}(2, '(null)(): suppl...', 'Unknown', 0, NULL)
#1 {main}
  thrown in Unknown on line 0

1.
这些错误从哪里来的?

2.
这些错误代表什么意思?

3.
有什么解决方案吗?