Hmm, that's strange. It is a pretty big file though ... over 2 gigabytes....but I would not have thought is was too big.
I would say it has become corrupted.
Fortunately alarmlog.tps is not a crucial file and can be deleted.
It contains a log of when alarms etc were added, modified, or executed.
If the information IS crucial to you then can you please email the file to me so I can try and fix the file. No promises though if it is badly corrupted.
To delete the file, exit KA, and then delete alarmlog.tps from the same folder KA is installed to.
Then restart KA and you should be ok.
To prevent the file from getting that big again there is a setting in the preferences where you can set the maximum number of days to be kept.
for a screen shot.
Perhaps 30 days might be a good idea.
Let me know how you get on.