Previously installed and working shipping module disappears

[amasters]

Our main shipping module (from a contribution) had been working perfectly until sometime after 10:00am yesterday when it suddenly stopped appearing in the checkout process.

*We made no changes to the files or tables involved or to the functionality of any file.

*We have uninstalled and reinstalled with no success.

*We have compared all involved files to the originals and have found no differences.

Does anyone have any suggestions as to what else we should be considering? (I have purposely left out information as to what module it is as it is apparent that it is not the contribution itself.)

 

Thanks for any consideration,

Anne, the Baffled