VLOOKUP Cell Referencing #VALUE Error

I'm working on a spreadsheet for a gaming community. This sheet is used by more than 3000+ players and growing. It has to be updated roughly twice a week for new inventory items, which can range from 1 to 3 new items weekly.

To make it easier on new and existing members, I want to create a way to make updates with the spreadsheet easier and to allow players an easier way of updating the spreadsheet rather than re-entering all the data over and over again twice a week.

So, I started to use VLOOK in some formulas to look at the data and pull the corresponding information. However, this same information is used throughout the sheet and referencing this information has brought about #VALUE errors that I cannot seem to figure out how to get around.

I've included a copy of the spreadsheet to download and review in hopes of finding a solution.

Here's what this speadsheet is doing:
MyInventory is where the players will enter all their items, with some being drop-down selections and manual entry.
The LookupedInventory worksheet is where the VLOOKUP (columns C,G,J,Q,etc.) formula is used to look up entries in the MyInventory worksheet and pull their values over to the LookupedInventory worksheet.
Now these values from the LookupedInventory will be carried over into two other worksheets, InventoryTableAttack and InventoryTableDefense. These two worksheets are where my #VALUE errors are appearing. If the cell referenced is empty, the #VALUE error appears. However, if the cell references a number, the rest of the formulas tied to to this cell reference work. However, since there are errors, the rest of the worksheet cannot function until I fix all the #VALUE errors.
So, what I'm seeking is to see where my issue is and what I need to do to fix it.

If I need to take a different approach to this, please let me know what that is and how to go about doing it.

I've even thought about a macros that copies and paste all the current data from an older spreadsheet to the new one, but I'm not that good at macros. If I can stay away from macros, that would be good, but if not, then I'll have to dig in my heels and start leaning.