Could not convert variant of type (Null) into type (Integer)

[Guest Molly]

This error can occur in a variety of circumstances. A few will be listed below.

A. Stratigraphy Modeling:

If this error occurs when you are trying to create a model or diagram under the Stratigraphy menu, check your Stratigraphy Types table to be sure that the units are numbered properly - the Order field must use integers from 1 to x, with 1 representing the shallowest unit, and subsequent units numbered sequentially downward.

B. Profiles, Sections, Fences:

If you see this error when you are trying to create a profile, cross section, or fence diagram, right before the map-picking window is displayed, the problem may lie with the borehol symbols. If the project's MDB file was generated using an external application and if no default symbol and color was selected for each borehole, the database may load fine into the Borehole Manager (RockWorks will just display a default design in the Location tab). You might also be able to create a borehole location map just fine (again, it will use a default). But it does cause problems when the profile-, section-, or fence picker is displayed. These interfaces are linked to use the color the user has defined for the borehole symbols (as a handy way of distinguishing them) and it delivers the error when no symbol is defined.

You can assign a symbol for each borehole by double-clicking on the symbol design on each borehole’s Location tab. Or, an easier way to assign a symbol for each hole is:

1. In the Borehole Manager, choose File / Transfer / Locations -> Utilities Datagrid. This will transfer the location records for all holes to the Utilities datasheet.

2. Double-click each cell in the Symbol column to select a symbol and color for the hole. If you want them all to be the same design & color, you can choose one interactively, and then copy/paste the remaining symbols in.

3. When you are done selecting symbols and colors, choose File / Transfer / Locations -> Borehole Manager from the Utilities menu. The program will transfer the location fields back to the database.

[Guest Molly]

In RockWorks16 we have discovered that a missing pattern number in the Stratigraphy Types table can also cause this error. Be sure all of the formations that you have defined in your Stratigraphy Types table have a pattern number assigned to them: Double-click in the pattern cell to choose the design from the Select Pattern window. You can choose pattern #0 if you don't want any design.

Molly Mayfield

RockWare Inc.