Problems while blocking - inform your system specialist

What causes this issue?

You wanted to create/delete assignments of measures. To protect
these assignments against parallel processing, you should make a
lock entry. However, an internal error occurred during this
process.

System Response

Processing canceled.

How to fix this error?

Inform your system manager, so that he/she can localize the problem.

Error message extract from SAP system. Copyright SAP SE.