3018643 - Syntax error in SAPLSEWORKINGAREA for method ACTIVATE_WBACCESS_SMODI_ENTRS during upgrade

While running SUM, phase MAIN_SHDIMP/SUBMOD_SHD2_RUN/START_SHDI_SHD2 fails with Syntax Error:

<< 2021/01/22 23:53:43  END OF PHASE   MAIN_SHDIMP/SUBMOD_SHD2_RUN/START_SHDI_SHD2
=========== Repeat Phase ===========

Severe error(s) occurred in phase MAIN_SHDIMP/SUBMOD_SHD2_RUN/START_SHDI_SHD2!

Last error code set:
Shadow instance
couldn't be started, check 'START_SHDI_SHD2.LOG' and 'DEVTRACE.LOG': Action START failed for <> ('Error
in call_upg_is_shadow_system.').
=
Name:         START_SHDI_SHD2.LOG

1 ETQ359 RFC Login to: 
2 ETQ232 RFC Login succeeded
2EETQ360 RFC of "UPG_IS_SHADOW_SYSTEM" failed:
2EETQ361 code/exception  : 3
2EETQ362 key             : SYNTAX_ERROR
2EETQ399 Syntax error in program SAPLSEWORKINGAREA                       .
1 ETQ399 Action START failed for <> ('Error in call_upg_is_shadow_system.').

The same error can occur in SPAM, the failure is in the execution of job RDDGEN0L:

Job started                                                                   00           516          S
Step 001 started (program RDDGENBB, variant CONM, user ID SAPNWFWK)           00           550          S
Start of conversion: 13:44:33                                                 AD           898          S
File log: <>                                                        D0           325          S
Internal session terminated with a runtime error SYNTAX_ERROR (see ST22)      00           671          A
Job canceled                                                                00           518          A

The following is the SYNTAX_ERROR that can be found in ST22:

Category               ABAP programming error
Runtime Errors         SYNTAX_ERROR
ABAP Program           SAPLSEWORKINGAREA
Application Component  BC-DWB-UTL-BRR

 Error in the ABAP application program.

 The current ABAP program "CL_OO_CLASS_BUILDER===========CP" had to be
 terminated because it found a  statement that could not be executed.
 In include "LSEWORKINGAREAFCC                       ", in line 159 of program
  "SAPLSEWORKINGAREA                       ", the following syntax errors have occurred:
 Method "ACTIVATE_WBACCESS_SMODI_ENTRS" is unknown or PROTECTED or PRIVATE.

SAP NetWeaver 7.5 after the implementation of SAP Note 3001279 version 2.

SAPLSDYY, RUTDDLSCREATE, LSDYYU13, CL_WB_PGEDITOR, XPRAS_SHD_AIMMERGE, SAP Note 3001279, syntax_error, SAPLSEWORKINGAREA, SEWORKINGAREA, START_SHDI_SHD2 , KBA , BC-DWB-DIC-ED , Data Dictionary Tools in ABAP Workbench , Problem