C:\Program Files (x86)\Wasp Technologies\InventoryControl\Labels is where the original copies of the labels are stored. These labels are used if the system starts to print and finds no working copy. The labels in this folder should never be edited.
C:\ProgramData\Wasp Barcode Technologies\InventoryControl\4.0.0.0\Labels is where the working copies are kept. If the label exists in this folder, that version will be used for printing. If the label does not exist in this folder, it will be copied from the Program Files folder into this one. If you make a mistake while editing and need to just go back to the original, delete it from this folder and it will create a new copy of the original the next time you print.
It could be printing blank labels for a few different reasons, depending on how you have linked the tables. If you used the AutoLink option, it most assuredly has done it incorrectly. You should only have 1 link between each pair of tables, and AutoLink will make every possible link. E.g., if 2 tables have 3 columns in common, like item_id, item_number, and item_description, and multiple other columns on each, AutoLink will pick all 3 of those columns as links, but you should have only 1 link, preferably the _id column if possible.
When printing from Inventory, the way the SQL query is generated will key off a different column, depending on which label you are printing. If you have linked tables, and the column the query uses to filter results is on both tables, the query will error out since the column name returns ambiguous results. Similarly, if you direct the label to a different table that does not include the column that the query is using, it will fail.
If you need this data all on a single label rather than printing separate labels for each piece of data, you have 2 options. We do offer a paid service where we will insert a new table into the database using just the columns you need, and create a custom label for you that will use that table. Please contact Wasp Sales for the current rate for this service.
On the other hand, you can create a label linking the multiple tables together as needed, and then print the label from Labeler directly rather than by calling it from InventoryControl. This way, it will not be restricted to the field that Inventory is trying to use as a filter, you can have the id fields on multiple tables without causing issues, and you can use the Select Records Now at print time to specify the results you want to print, rather than depending on the program's ability to construct the filter.