Hi Ilya,
If you have not done so already, can try the following?:
1. In Inventory Manager select one of the Cisco switches
2. To the right, click on the Image Information tab
3. in the MIB and Script Overrides section, for Firmware Download MIB select Script, for the Configuration MIB select Script. For the Device Family Definition File Name, select Cisco Systems-TFTP
4. Click Save on the far right of the window
Confirm that the SNMP profiles/credentials are correct and see if the config download works.
Regards
Tony