2500568 - Software Update Manager stops in MAIN_SHDRUN/ACT_UPG phase, with many errors informing that standard SLT tables could not be activated

During an upgrade, the Software Update Manager (SUM) stops in MAIN_SHDRUN/ACT_UPG phase, with many errors informing that standard SLT tables could not be activated.

=== ACTUPG.ELG ====================================
3 EDT012XActivate table "/1CADMC/S0000217" 
2WEDT202 Specify a delivery class from the set ("A,C,E,G,L,S,W")
2WEDT192 Enhancement category for table missing
2WEDT193 Enhancement category for include or subtype missing 1EEDT211 Field "VARDATA" (Length > "255" for "RAW" only allowed for non-DB tables)
1EEDT617 Maintain size category for table "/1CADMC/S0000217"
3 EDT013 Table "/1CADMC/S0000217" was not activated

3 EDT012XActivate table "/1CADMC/S0000223"
2WEDT202 Specify a delivery class from the set ("A,C,E,G,L,S,W") 
2WEDT192 Enhancement category for table missing 
2WEDT193 Enhancement category for include or subtype missing 
1EEDT211 Field "VARDATA" (Length > "255" for "RAW" only allowed for non-DB tables) 
1EEDT617 Maintain size category for table "/1CADMC/S0000223" 
1EEDT616 Maintain data class for table "/1CADMC/S0000223" 
3 EDT013 Table "/1CADMC/S0000223" was not activated 
1EEDO519 "Table" "/1CADMC/S0000223" could not be activated
================================================

The table informed in the logs may vary, including some /1LT/* tables:

=== ACTUPG.ELG ====================================
3 EDT012XActivate table "/1LT/20200000333"
1EEDT211 Field "VARDATA" (Length > "255" for "RAW" only allowed for non-DB tables)
3 EDT013 Table "/1LT/20200000333" was not activated
1EEDO519 "Table" "/1LT/20200000333" could not be activated

================================================

"255" for "RAW" only allowed for non-DB tables , KBA , BC-UPG-TLS-TLA , Upgrade tools for ABAP , BC-DWB-DIC-AC , ABAP Dictionary Activation and Conversion , Problem