Template:FAQ:MIBs 05

If this error is only generated for one or two modules, then it's likely that the named modules are not being found - perhaps they're not installed in the correct location, are not readable, or the name being used is incorrect. Note that the name reported is the name of the MIB module, which is not necessarily the same as the name of the file. See the question How do I add a MIB to the tools? for more details on this.

If there are a large number of such errors, then it's more likely that either the MIB files haven't been installed at all, or the library is looking in the wrong place for them.

Try running snmptranslate -Dparse-mibs to see where the MIB files are expected to be found.