Open Spreadsheet out of memory

How can I increase the Java Heap memory?


Hi @gonzalomelov.
When do you receive this exception? During playing recording?

Yes, when I hit play.

I will be trying using the background bot right now in order to check that is a different java process running

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Thanks. Let me know whether you find it. Also screenshot of the exception will help :slight_smile:

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Same error using the background bot runner

Attached follows the exception of the runner

exc.txt (7.9 KB)

I forgot to point that the Excel file is like 200mb

Thanks. So 200mb is enough big file. You can read about max Excel file size in this thread: Max files size for RPA Express Excel function

In your case, there are 2 possible solutions.
The first is to use small Excel files. You can try to divide your original file to several files and process them in loop.
The second option is to increase memory for Java machine, but it can affect performance of other applications and whole performance of your PC. To do it, you can go to the file “start-node0.bat” and edit option Xmx512m to Xmx1024m, for example.
If you want to try with the second option, please stop RPA Express and then edit this file.

Hope this information helps you.


Awesome!!! I will try the 2nd approach and come back to you with the results!!




I am trying to process excel file having 10 lacs records and 60 columns.
While loading that file for reading, it is giving me error : OutOfMemoryError: GC overhead limit exceeded”.
I don’t want to use external jars.
Is there any way to process such large files by using existing workfusion jars?
Is there any better way to handle these types of files?


Hi @smalavi.
Did you try some of approaches described in post above?

Finally I had to use a Python script to use the Excel file



Hi Lera,
Thank you for your quick response.
1)To divide your original file to several files, we have to load the file first and it is failing at that step only.
2)We are running from control tower. Will second option of increasing java memory work here?

Thanks and Regards,
Shubhangi Malavi

Hi gonzalomelov,

Thank you for your response.
Can we use Python in Workfusion with existing jars? I don’t want to use external jars. Can you send me useful links to do that?

Thanks and Regards,
Shubhangi Malavi

Yes, that should work, but you need to update all start-node[X].bat files in case of multiple bots.

Not Recording.
I am trying to run script.

We have executed the Python script using Win + R

I don’t think you can execute it using existing jars

Hi Lera,
I have a issue as java heap memory error same as above. In my process i am saving 2 excel sheets into two tables (table1, table2). Both excels have date and amount columns and table 2 contain ID column . so i have to check date and amount are matching for each row and get id in corresponding row . so i am using nested for each loop and saving the matched id into a list. The no.of columns present in table1 is around 800 and that of table2 is around 1800.

This is the screenshot of the code:


This is the code i am using in UnMatched Records custom script:

input = ['remElements','DRElements'],
output = 'unmatched_records_list'

 def customScript(){
  	def num1 = RNumber.fromCanonical(remElements[11])
  	def num2 = RNumber.fromCanonical(DRElements[5])
 	if((remElements[7] != DRElements[3])&&((num1 != num2) || ((num1 <=(num2+1))&& 
 (num1 >=(num2-1))))&&(!((remElements[7]) in (unmatched_records_list))) ){
 		unmatched_records_list = unmatched_records_list+remElements[7]

When i am trying to run this code i am getting java heap outofmemory error :

So, I am forced to use open excel of table1 using WIN + r and other excel in the background. the process is taking approx 30 minutes by using this logic . can you help me with this.

PS: I trying to increase the heap memory upto 4Gb but the issue is still not resolved.

Thank you in advance.