It's likely that Sage won't be able to assist you with complex imports, such as the Assembly Journal. Certified Consultants are your best source for assistance with this type of problem. When we have encountered this with other clients, or during rebuilds that we do for clients inhouse, we have found that this type of error occurs when you are trying to import the build of an Assembly, but you don't have enough of one or more of the components needed for the build on hand. To troubleshoot this, attempt to manually enter one of the Assemblies that you are trying to import, and then see if Sage gives you an error when attempting to save the build. The Assemblies Build screen will actually show you which components you are short on, which keeps the actual build from taking place. For additional assistance with this issue, please reach out to us at https://pcosupport.com. 

Thank you for replying and giving me some guidance.  It's pathetic when a company who designs software doesn't support it or offer you any assistance, even when you pay for their support package.  I've been at this for the past two months and it's been extremely frustrating.  Thankfully for me, persistence pays off. 

I was actually able to successfully import the assemblies journal yesterday.  It's a long and cumbersome process, but I was able to get it work with the exception of a few errors that I'm working on now.  The errors I'm getting are with the assemblies with serial numbers, but I believe that's because those transactions were imported before the Assembly Journal was imported.  For some reason Sage doesn't allow you to import an assembly item with the date from a previous period, so you must change the "Date" field to the current period.  Additionally, you have to use only one line from each Assembly Item ID (some of mine have over 50 lines) and change the "Number of Distributions" field to "1".  The only exception to this is if it's an assembly item with a serial number, you must have two lines for that Assembly Item ID and enter a "2" in the Number of Distributions field (or if there were multiple serial numbers for that assembly, adjust the lines and number of distributions field accordingly). 

I'm still working on importing everything correctly and cleaning things up, so I'll post another update with the entire process for other users to see, in case they run into this same problem in the future.

Your comment "Sage doesn't allow you to import an assembly item with the date from a previous period" is actually incorrect. This morning, with another client, I imported assemblies from 3.5 years prior to the current period and everything imported without problems. In addition, all of those assemblies we imported had serial numbers, and yes - to agree with you, the number of distributions had to be 1, because it's a 1-to-1 relationship between the serial number and what is being built. For example, if you build 5 of something, your import file would have 5 lines, each of which show a number of distributions as 1 each, each with it's unique serial number. For adjustments, it's one line per ID. For Work Tickets, you can have multiple lines. It just depends on what you are importing. We are here to help, so please let us know if we can be of any assistance as you move forward.