Hello again Valerie,
I suspect that the APGLDS files were corrupted due to the problems with the network. These files contain the information that is displayed when you view Transactions and choose Applied. They are the distribution details for a document that are displayed in the last section.
The information can also be printed on a Vendor Transactions report if you turn on the option, Include G/L disbursement details. It is not the same as the matching documents or as the information that is transferred to the General Ledger. To see the section I am referring to, look at Sample data, Vendor COM02, Invoice 16-2. The distribution details show a debit to Account 6300 and a credit to Account 2100.
To test my theory, make a copy of the data and rename the two files on the copy. When you open this copy of Adagio Payables data, new files will be created. If you do not get the error, you will need to decide how valuable the information in the old files is. If it is really valuable, you will need to get the data repaired.