I downloaded PCU version 3.2 which includes solarworx library 3.5. I would like to update to solarworx version 3.8 because it has FB which is not in v3.5. When I replace the library I get the error as shown below.

The issue is having more than one version of the PLCnextBase app. Whether that library is loaded in the project, or a dependency of another library, each instance must be the same version.
Ok, but I need a version of solarworx 3.8 where the Base library dependency is 1.6.3 as well as IPMBsc where Base is 1.6.0? Where can I download IPMBsc which has a dependency on Base 1.6.3?
Ok, but I need a version of solarworx 3.8 where the Base library dependency is 1.6.3 as well as IPMBsc where Base is 1.6.0? Where can I download IPMBsc which has a dependency on Base 1.6.3?</p>
Please contact the developer of the IPMBsc library. They should be able to help with this question.