Verify files exist:
If libraries were recently patched or OS packages were updated, the Oracle binary might need to be re-linked. Verify files exist: If libraries were recently patched
: Close web browsers or other heavy applications to free up RAM. Adjust Oracle Memory your NLS_LANG was misconfigured.
When SQL*Plus starts, it tries to dynamically load these libraries. If any of them are missing, inaccessible, or incompatible, the loader throws Error 57. Verify files exist: If libraries were recently patched
Then try running sqlplus /nolog . If that works, your NLS_LANG was misconfigured.