Item preprocessing step #1 failed: (null)

[Dusty]

After the upgrade from version 3.4 to 3.4.1, log messages of the form:

2405:20170830:101742.868 item "Catalyst 3:ifOutOctets[FastEthernet0/5]" became not supported: Item preprocessing step #1 failed: (null)
2406:20170830:101749.890 item "B1:ifInOctets[FC port 0/2]" became not supported: Item preprocessing step #1 failed: (null)
2406:20170830:101749.890 item "B2:ifInOctets[FC port 0/7]" became not supported: Item preprocessing step #1 failed: (null)
2403:20170830:101843.056 item "Catalyst 3:ifOutOctets[FastEthernet0/5]" became supported
2406:20170830:101849.067 item "B1:ifInOctets[FC port 0/2]" became supported
2404:20170830:101851.080 item "B2:ifInOctets[FC port 0/7]" became supported
2405:20170830:101928.159 item "insideA:ifOutOctets.10119" became not supported: Item preprocessing step #1 failed: (null)
2404:20170830:101943.193 item "insideA:ifOutOctets.10119" became supported
2403:20170830:102429.813 item "insideA:ifOutOctets.10106" became not supported: Item preprocessing step #1 failed: (null)
2403:20170830:102444.851 item "insideA:ifOutOctets.10106" became supported

So with all devices that are polled by SNMP.

There are a lot of them, we had to disconnect the devices from monitoring.

Help!