POS error on start: More than one export was found that matches the constraint
POS cannot start and shows the error ‘Error number: 1300 could not load all external service modules.
Reason and Solution
Some standard DLLs have been deployed to multiple folders. For example, Transaction.dll exists in POS root folder and was deployed to ‘Extensions’ folder by mistake.In this case deletion of Transaction.dll from ‘Extensions’ folder will solve the issue.