Bugs been fixed in the ABS extension

[Antti-L]

There was a bug introduced in v4.6.9 related to one equation in the ABS extension (EQ_BS24, end-use negative reserves). This bug was caused by a side-effect from the enhancements in v4.6.9 (which were of general nature) to the formulation of that single equation, which had been left unnoticed. The issue was reported in late August 2024, after which it was quickly fixed in v4.8.3. At the same time, also another bug related to one ABS equation (EQ_BS09) was noticed and fixed. The second bug was related to reserves provided by past investments in power plants without dispatching modelling, and had not been manifested in the ABS demo models.

Consequently, any users of the ABS extension are encouraged to use the latest version to avoid getting hit by these two unfortunate bugs.