In the picture given, you can see that here 8 digit ISIN code has been entered instead of 12 digit, so this error is coming.
You must correct these isin codes to correct these errors. (Go into transactions → Capital Gain Head → select capital gain entry).

Many times it happens that we do not enter ISIN code manually and copy it from some other format and other places , In such situation, some gap or space comes in the ISIN code and the entire code does not reflect in xml ,. If this happens, then you have to enter ISIN code manual
Hope this helps