In the following you can find two examples with deleted or hidden table rows:
A table restriction [Restricted display] TYPE.EQ.40 was set for the table_filter.prj project.
This table restriction is saved in the prj file. So this adding does not result in a new table version. That's why the project is not displayed in the mapping.
For the project din_28129.prj, all lines that contain a value in the variable D2 that is not an integer have been deleted.
Initial situation: In rows containing a not integer value, check if the table on the right side is hidden. In this example this is not the case, so that a condition has to be added.
Formulate a condition which only allows correct values (in this case "Integer")
D2.EQ.INT(D2)
Enter the condition. You can find explanations of the syntax under Section 7.8.12.6, “Mathematical functions (feature algorithm ) ”.
-> Rows which cannot be assigned are marked with a red X.
Select row without target project -> No table is displayed on the right.
Select rows with assigned target project -> The table of target project is displayed on the right. The correct row is marked
.If the desired behavior is shown, verify all lines (whether with or without a target line) by clicking on Confirm all assignments [Verify all mappings].
The example contains a small flaw: The variable D2 should actually be part of the NB. If it were, the change icon 
would be displayed in the tree. The explanations above are not affected by this and are correct.