Excel Error: Exception from HRESULT: Ox800A03EC

We have developed a .dll file to handle change requests in PDM. However, while performing check-in and check-out operations in PDM, we are encountering the following error message:

"Excel Error: Exception from HRESULT: 0x800A03EC"

We would like to understand the root cause of this issue and would appreciate your assistance in identifying possible reasons for this error.