This is a known issue in ioGAS, and is caused by having a certain number of checkpoints in an ioGAS file. This number is indeterminate, which varies between the size of the ioGAS file, the users’ computer specification and which ioGAS executable file the user is running. There are two workarounds for the time being: 1) If you are noticing that your ioGAS file is not saving, delete checkpoints from the file and try saving the file again. 2) start a new session and do not use checkpoints – save multiple copies of the .gas file instead.
Please contact firstname.lastname@example.org if you require further assistance.