SSIS Package Error After Upgrade to Office 365

I have an SSIS package that connects both to Excel and SQL Server that worked fine up until our office upgraded to Office 365. I created "Connection Managers" for both of the connections (Excel and SQL Server) after researching and finding this might be the solution, but to no avail (and this was not required when running successfully). I've adjusted the Properties Configuration Properties/Debugging and set Run64BitRuntime to False - another thread I found indicated to do this. I am not experienced in SSIS beyond just running packages - I inherited this from a co-worker when they retired. Following is the error message:

SSIS package "c:\docusign bh pdv triage\sql server\ssis\docusign bh pdv macro output\BH_PDVM_OutputToExcel.dtsx" starting. Executing ExecutePackageTask: c:\docusign bh pdv triage\sql server\ssis\docusign bh pdv macro output\BH_PDVM_CreateExcelWorkbook.dtsx Executing ExecutePackageTask: c:\docusign bh pdv triage\sql server\ssis\docusign bh pdv macro output\BH_PDVM_CreateExcelFileFromTemplateFile.dtsx Executing ExecutePackageTask: c:\docusign bh pdv triage\sql server\ssis\docusign bh pdv macro output\BH_PDVM_CreateExcelWorksheets.dtsx Information: 0x4004300A at Create Worksheet 1099, SSIS.Pipeline: Validation phase is beginning. Error: 0xC0202009 at BH_PDVM_CreateExcelWorksheets, Connection manager "Excel Template": SSIS Error Code DTS_E_OLEDBERROR. An OLE DB error has occurred. Error code: 0x80004005. An OLE DB record is available. Source: "Microsoft JET Database Engine" Hresult: 0x80004005 Description: "External table is not in the expected format.". Error: 0xC020801C at Create Worksheet 1099, WORKSHEET - 1099 [147]: SSIS Error Code DTS_E_CANNOTACQUIRECONNECTIONFROMCONNECTIONMANAGER. The AcquireConnection method call to the connection manager "Excel Template" failed with error code 0xC0202009. There may be error messages posted before this with more information on why the AcquireConnection method call failed. Error: 0xC0047017 at Create Worksheet 1099, SSIS.Pipeline: WORKSHEET - 1099 failed validation and returned error code 0xC020801C. Error: 0xC004700C at Create Worksheet 1099, SSIS.Pipeline: One or more component failed validation. Error: 0xC0024107 at Create Worksheet 1099: There were errors during task validation. Error: 0xC0022102 at EXEC PKG BH_PDVM_CreateExcelWorksheets: Error 0xC0012050 while executing package from project reference package "BH_PDVM_CreateExcelWorksheets.dtsx". Package failed validation from the ExecutePackage task. The package cannot run.
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Task failed: EXEC PKG BH_PDVM_CreateExcelWorksheets Warning: 0x80019002 at BH_PDVM_CreateExcelWorkbook: SSIS Warning Code DTS_W_MAXIMUMERRORCOUNTREACHED. The Execution method succeeded, but the number of errors raised (6) reached the maximum allowed (1); resulting in failure. This occurs when the number of errors reaches the number specified in MaximumErrorCount. Change the MaximumErrorCount or fix the errors. Task failed: EXEC PKG BH_PDVM_CreateExcelWorkbook Warning: 0x80019002 at For Each Batch Macro File: SSIS Warning Code DTS_W_MAXIMUMERRORCOUNTREACHED. The Execution method succeeded, but the number of errors raised (6) reached the maximum allowed (1); resulting in failure. This occurs when the number of errors reaches the number specified in MaximumErrorCount. Change the MaximumErrorCount or fix the errors. Warning: 0x80019002 at BH_PDVM_OutputToExcel: SSIS Warning Code DTS_W_MAXIMUMERRORCOUNTREACHED. The Execution method succeeded, but the number of errors raised (6) reached the maximum allowed (1); resulting in failure. This occurs when the number of errors reaches the number specified in MaximumErrorCount. Change the MaximumErrorCount or fix the errors. SSIS package "c:\docusign bh pdv triage\sql server\ssis\docusign bh pdv macro output\BH_PDVM_OutputToExcel.dtsx" finished: Failure. The program '[16304] DtsDebugHost.exe: DTS' has exited with code 0 (0x0).