EPiServer is not logging error when deployed in IIS server? There is no log file in App_Data folder.
Apologies if this is too obvious but have you confirmed that the EPiServerLog.config file is being deployed with the application?
And if it does, then check the path specified in that, it is not default to App_Data. also make sure user assigned to IIS app pool has write access to that folder
EPiServer is not logging error when deployed in IIS server? There is no log file in App_Data folder.