Error log in export step:
invalid value ‘E’ in E071.LANG (as4pos = 000013)
R3TRTABUPPFTFLTVAT
Incorrect export. Request not imported.

LANG_error

Solution:
1. Make sure you have the updated R3trans and tp program from SAP Marketplace.
2. Create new report ZRSWBO_CLEANUP_LANGFLAGS and run it.
3. Try to release your transport request.

Source code of ZRSWBO_CLEANUP_LANGFLAGS: