Dear Alain,
On behalf of Y Soft I would like to comment on this question.
First, there are very little details based on which I can provide any recommendation. Anyway, scan to folder may be part of YSoft SafeQ or not. If it is then the most common issue is the correct setting of access rights. Based on the version and architecture of YSoft SafeQ you use the main service responsible for scanning (CML AND/OR ORS) must run using credentials that have access to the destination network location.
From the support perspective this issue is best resolved while consulting your local supplier of your print fleet who is at the same time your direct contact for YSoft SafeQ related issues. Be it Xerox directly or a Xerox reseller. Also our partners (Y Soft as a company does not use direct selling business model) are trained to provide the support you require and distinguish the root cause of the issue.
In case the above recommendation did not resolve the issue please do contact your supplier of the print fleet.
Thank you for understanding.