You will get a Material Usage Varaiance for everything in the WO Bill that was not issued (in your case, apparently, everything!)
To fix it, re-open the WO by going to 16.1 and changing the status to R. Now process all the issues using 16.10, return to 16.1 to close the WO again and repeat the WO Accounting Close. It will recalculate the variances & post correcting GL transaction for the delta.
Duncan Jones
Duncan Consulting Ltd