Added a known issue

downloads/hdf4/hdf4_3_0.md

@@ -21,8 +21,12 @@ Applications that were created with earlier HDF4 releases AND employed internal
 
 |  File  |  Type |  Install Instructions  |
 | ----- | ---- | --------------------- |
-| [hdf4.3.0.tar.gz](https://github.com/HDFGroup/hdf4/archive/refs/tags/hdf4.3.0.tar.gz) ([sha256](https://github.com/HDFGroup/hdf4/archive/refs/tags/hdf4.3.0.sha256)) | Source release   ||
-| [hdf4.3.0.zip](https://github.com/HDFGroup/hdf4/archive/refs/tags/hdf4.3.0.zip) ([sha256](https://github.com/HDFGroup/hdf4/archive/refs/tags/hdf4.3.0.sha256)) | Source release    ||
+| [hdf4.3.0.tar.gz](https://github.com/HDFGroup/hdf4/archive/refs/tags/hdf4.3.0.tar.gz) | Source release   ||
+| [hdf4.3.0.zip](https://github.com/HDFGroup/hdf4/archive/refs/tags/hdf4.3.0.zip) | Source release    ||
 | [Ready to use Binaries](https://github.com/HDFGroup/hdf4/releases/tag/hdf4.3.0)  | Pre-built binary distributions for Unix and Windows |
+| [sha256](https://github.com/HDFGroup/hdf4/releases/download/hdf4.3.0/sha256sums.txt) | Checksum file   ||
 
 Please refer to [Build Instructions](https://raw.githubusercontent.com/HDFGroup/hdf4/master/release_notes/INSTALL.txt) for building with either CMake or Autotools.
+
+#### Know Problems:
+Some SZIP tests in mdfhdf failed when the SZIP encoder is not present and the failure can be ignored at this time.