Hello,
It is a known issue, which will be solved in 7.3 firmware, related to a missing dependency, when compiling final firmware, which leads to SNMP traps package simply not being installed. To solve this, you need to upload SNMP package manually via Services > Package Manager > Upload page, the package can be downloaded from here.
Otherwise, you need to access the router via CLI (In the web UI navigate to System -> CLI) or SSH (you can use PuTTy) client and execute the following commands:
- opkg update
- opkg install snmptrap
Best regards,
Žygimantas