Hi Mark,
Based off the error it may be something with the length of the APM name, or possibly an invalid character.
Was this an APM you have been able to open in the past? If so, what version of ArcPad was it originally created in?
Its important to note that all other ArcPad versions before 10.2.5 have now been retired, so I would suggest you attempt updating the software if you haven’t already to see if potentially there was a bug that’s now fixed.
Is this the only APM you are seeing this error with?
