SAP Note 27959 - Route determination: Info VC203 'System error ...'

Symptom:

Transaktion VORF, route determination, detail screen 'weight group route':
Screen shows one or more lines with weight group = blank and a related text <> blank (e.g. 'up to 10 kg'). Pressing a key like or on this screen causes an info message 'System error occurred reading internal table XD0400'. This message might pop up several times.

Cause and prerequisites

Table TVLGT (Routes: Weight Groups for Deliveries: Texts) contains an entry with weight group = blank and text <> blank.
Second possible cause is that table TVROT (Route texts) contains an entry in login-language with route = blank and bezei <> blank.

Solution
Remove entry from table TVLGT or TVROT (e.g. via transaction SM31 or SE16).