'Call rejected by callee' error occurs when the instance (of Excel) that you are connected/connecting to is currently in an interactive mode.
To resolve the problem, try out the following :
Solution 1
If you are using Excel 2016 or higher, you may get the aforesaid error "Call was rejected by callee'" while importing data using udiMagic. To resolve this issue, upgrade to udiMagic v9.0 Release 1.3 or higher.
IMPORTANT
The excel templates in udiMagic v9.0 may be a bit different from the earlier version/release. Hence, kindly ensure that you put your data into the new templates only and upload using the new templates only.
Solution 2
Close MS-Excel and then retry importing data into Tally using udi-Magic. If problem persists, then try out the Solution 3 given below.
Solution 3
Create a new Excel Workbook and copy/paste the data from your original Excel file into the new workbook. Next, try importing data from the New Workbook/Excel file.