# SAP ERP JDBC: “sapjco3.dll already loaded in another classloader” when used from Jaspersoft Studio

**URL:** <https://community.cdata.com/t/sap-erp-jdbc-sapjco3-dll-already-loaded-in-another-classloader-when-used-from-jaspersoft-studio/1246>\
**Category:** Data Sources\
**Tags:** jaspersoft, jvm, article, jdbc, sap-erp\
**Created:** [December 2, 2025, 4:35pm UTC](https://community.cdata.com/t/sap-erp-jdbc-sapjco3-dll-already-loaded-in-another-classloader-when-used-from-jaspersoft-studio/1246 "2025-12-02T16:35:05Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![James\_B](https://sea3.discourse-cdn.com/cdata/user_avatar/community.cdata.com/james_b/32/1688_2.png) [@James\_B](https://community.cdata.com/u/James_B)\
**Post date:** [December 2, 2025, 4:36pm UTC](https://community.cdata.com/t/sap-erp-jdbc-sapjco3-dll-already-loaded-in-another-classloader-when-used-from-jaspersoft-studio/1246/1 "2025-12-02T16:36:04Z")

</div>

The&nbsp;CData&nbsp;SAP ERP driver uses the&nbsp; **sapjco3.jar** &nbsp;dependency, which must be referenced in the&nbsp;classpath. This JAR, in turn, depends on&nbsp; **sapjco3.dll** , whose path must be added to the&nbsp; **PATH** &nbsp;system environment&nbsp;variable.

When using the SAP ERP driver from&nbsp; **Jaspersoft Studio,** you&nbsp;may&nbsp;encounter&nbsp;an issue where the driver works for the first connection but fails on&nbsp;subsequent&nbsp;attempts. Depending on where the operation is executed, you may see the following error:

_Error getting the version of the native layer:&nbsp;java.lang.UnsatisfiedLinkError: Native Library C:\<path-to-library\>\sapjco3.dll already loaded in another&nbsp;classloader_

This happens because Jaspersoft Studio closes the driver after completing an operation and later tries to reopen it. When the driver is reloaded, it&nbsp;attempts&nbsp;to use&nbsp; **sapjco3** , which in turn tries to load its&nbsp; **sapjco3.dll** &nbsp;dependency again. However, since&nbsp; **sapjco3.dll** &nbsp;is already loaded in the Jaspersoft Studio JVM, it cannot be loaded a second time&nbsp;resulting in the error mentioned above.

To mitigate this issue, instead of adding&nbsp;\*\*sapjco3.\*\*jar&nbsp;to the&nbsp;classpath&nbsp;of the individual data adapter, you can configure it globally within Jaspersoft Studio. This ensures that&nbsp; **sapjco3.dll** &nbsp;is loaded only once.

**Steps to Configure**

1. **Place sapjco3.jar in the Jaspersoft Studio directory,** as shown below:

2. **Edit the Jaspersoft Studio.ini file:** &nbsp;  
Add the following switch after the&nbsp; **-vmargs** &nbsp;tag:

**-Xbootclasspath/a:sapjco3.jar**

Save the file after making this change.

 ![d85371ae-6abc-4081-bf95-fdd47bc0926c.png](https://us1.discourse-cdn.com/cdata/original/1X/8be7b61ea23327b8712efc83b12519f3bbd3e4ae.png)

1. **Add the path of the directory&nbsp;containing&nbsp;sapjco3.dll to the&nbsp;PATH&nbsp;system environment variable.**

 ![95fe8efa-cbcc-4d4b-9205-65e67c6bb2ed.png](https://us1.discourse-cdn.com/cdata/original/1X/ac1bdf6e6ab5bc833349b21c46881e2e46a7a3d5.png)

1. **Start Jaspersoft Studio** &nbsp;and, when creating a Data Adapter, reference only the&nbsp;cdata.jdbc.saperp.jar&nbsp;file.

 ![2135b702-f880-4e79-98eb-95a1313be7fe.png](https://us1.discourse-cdn.com/cdata/original/1X/889343902512d74b78f37818d1e2314d89248183.png)

After completing these steps, you can successfully use the Data Adapter when creating reports in Jaspersoft Studio without&nbsp;encountering&nbsp;the “already loaded in another&nbsp;classloader” error.

If the issue persists, please&nbsp;contact&nbsp;_support@cdata.com_.