Is not a valid module name

[ynocquet]

Hello,

Since today (around 9 am), the error "is not a valid module name" is shown when _PS_MODE_DEV = true on version 1.6.1.1 on two different shops I have (with different folders  and without any core modification) and prevent any access to the back office.

The error is likely to come from Prestashop.

How to fix the error ?

Thanks,

Edit: the error has disappeared at 12 am.

Edited March 9, 2018 by ynocquet (see edit history)