Message Oracle PLS-00214 - BEGIN...END block nesting is too deep

ERRORBEGIN...END block nesting is too deep
CAUSEThe number of levels of nesting in the PL/SQL block is too large. Blocks can be nested up to 255 levels deep, depending on the availability of system resources such as memory.
ACTIONReorganize the block structure to avoid nesting at too deep a level. For example, move the lowest-level sub-block to a higher level.