Did the upgrade and ran in to a bunch of DCI changed to unsupported alarms. All of the DCIs in question were supplied by external parameters from files in /etc/nxagentd.conf.d/. After some digging it seems that ConfigIncludeDir no longer defaults to /etc/nxagentd.conf.d/ but has to be set manually in /etc/nxagentd.conf.
A bit confusing when the log states Additional configs was loaded from /etc/nxagentd.conf.d on agent start even before adding ConfigIncludeDir.
Update...
Changing the transformation script to this works
return int64($1) / (1024 * 1024);
Hijacking this thread as I'm seeing the same error with transformation of uint64 after upgrade to 2.2.1
DCI in question is Filesystem.Free(/var)
Transformation script after trial and error
trace(0, $node->name . " " . $dci->name . " " . $1 . " " . typeof($1));
return uint64($1 / (1024 * 1024));
Relevant part from log when above DCI is polled
2017.12.12 03:57:13.034 *I* alina FileSystem.Free(/var) 58124193792 uint64
2017.12.12 03:57:13.034 *W* Failed to execute transformation script for object 865 "alina" DCI 813 "FileSystem.Free(/var)": Error 13 in line 2: Cannot do automatic type cast
Also tried without casting to uint64.
Changing the transformation script to return null (which from my understanding of the hint should return the raw value) results in free space being reported as 0. Actual value printed to log for reference.
Transformation script
trace(0, $node->name . " " . $dci->name . " " . $1 . " " . typeof($1));
return null;
return uint64($1 / (1024 * 1024));
Log
2017.12.12 04:07:10.221 *I* alina FileSystem.Free(/var) 58124161024 uint64
Transformation script before update was simply
$1 / (1024 * 1024)
Clearing out the transformation script returns the raw value.