How To Fix TG436 - Unable to open file & (see long text for this message)

SAP Error Message - Details

• Message type: E = Error

• Message class: TG - Messages for Upgrade Repository Switch

• Message number: 436

• Message text: Unable to open file & (see long text for this message)

What causes this issue?

The file REPLIST, which contains the names of all the ABAP programs
that were generated before the upgrade, could not be opened. Either the
file does not exist or there is no read authorization.

System Response

The selection of objects for the Load Generator is not valid. The
program lets you make a new selection.

How to fix this error?

Check if the correct group is selected and if all the paths and file
descriptions are correct.
If access to the file REPLIST is still denied, on the initial screen of
transaction SGEN choose 'First generation after an R/3 installation'
instead of 'New generation after an R/3 upgrade'. Select the software
components and application servers once again.

Error message extract from SAP system. Copyright SAP SE.