I'm getting this when trying to create the assembly on SQL 2005 SP2.
CREATE ASSEMBLY for assembly 'tSQLtCLR' failed because assembly 'tSQLtCLR' failed verification. Check if the referenced assemblies are up-to-date and trusted (for external_access or unsafe) to execute in the database. CLR Verifier error messages if any will follow this message
[ : tSQLtCLR.tSQLtPrivate::getTableStringArray][mdToken=0x6000012][offset 0x00000179] Unable to resolve token.
[ : tSQLtCLR.tSQLtPrivate::SqlDateTimeOffsetToString][mdToken=0x6000017] Type load failed.