Sometimes, you may receive an email stating that ApprovalMax can't connect to Xero due to the "5015 - Failed to validate signature" error.
There is an ongoing technical issue that we currently can't overcome: the Xero connection breaks up if a Purchase Order has a file attached that contains some specific symbols, which Xero does not accept.
In ApprovalMax, we have prohibited attaching files that contain any of the banned symbols. But although we know most of them, we occasionally discover new banned symbols, and, unfortunately, we are not able to get a complete list of all prohibited symbols.
This is how you can fix the problem:
In any case, please contact us and we'll investigate which file (and which specific symbol) is causing the problem and provide a fix to prevent attaching such files in the future.
You can also try to find out for yourself which file is causing the problem and remove it from the Purchase Order.