What are common transport errors

Return code (4) indicates imported ended with warning.
Ex:
1. Generation of programs and screens
2. Columns missing and Rows missing.

Return code (8) indicates not imported ended with error
Ex:
1. Syntax error.
2. Program generation error.
3. Dictionary activation error.
4. Method execution error.

Return code (12) indicates import is cancelled.
Ex:
1. Import is cancelled due to object missing.
2. Objects are not active.
3. Program terminated due to job ?RDDEXECL? is not working.
Return code (16) indicates import is cancelled.

Ex:
1. Import cancelled due to system down while importing.
2. Import cancelled due to user expires while importing
3. Import cancelled due to insufficient roles.