Hi Vivek
The issue is happening on the availability check, probably because the lead time of a component is too big. The availability date of the material is material specific and is based on planned delivery time (in calendar days) + GR processing time ( in work days) + Purchase processing time. If one of these values is too big, the date will be calculated in 2016, which is outside the validity of the factory calendar, so this error is triggered.
If you want to know exactly for which component this is happening, you can use the procedure described on the documentHow to analyze an error message in debug and check it in debug.
Nevertheless, it will be still necessary to adjust your factory calendar and extend it far in the future, to avoid this kind of issue.
If you research on SCN, you will find several old threads where the extension of the factory calendar was discussed. You will also find WIKI Factory Calendar validity until 2010 - Netweaver Technology - SCN Wiki, which should be useful to you.
Best regards
Caetano Almeida