In our IT based startup, we have many leads who use old (really really old, like 3-4 years) project folder, and modify them for new projects for clients.
I was working on a project, say Project 1. A chunk of it was completed, so I started working on Project 2 simultaneously, and because my manager told me so.
What I didn't know was that the Project 2, was actually an older version of another project, where a lot of modifications were done. So, if the older Project were called Project X (which was completed some 4 years back, with say PHP version 7), say Project X was for healthcare system, while Project 2, was for an E-commerce system. So, Project X was being modified for Project 2. I was unaware of this, so I asked my team lead, which version it was, so that I could look up for proper documentations. Apparently, the team lead too was unsure of this, however he guessed it to be PHP 7.4, and I followed that version.
It so happened that the servers where these files were hosted did not accept these old versions. The version requirement was PHP 7.4 or more. I had updated my version of PHP and even the version installed onto the servers are updated. It would run on my laptop, my colleagues' laptop, and even on a different server, where lower versions are used.
However, the project folder had PHP 7.0. The team lead was unwilling to update his version. When the server did not open anything, not even a connection to the database, the team lead started calling me and told that my code does not work. He would do this every day, 5-6 times a day.
Now, I had to focus on Project 1 due to some client requirement changes. However, the team lead is asking me to complete Project 1 even if I were to work on weekends, so that Project 2 could be done by me, as the project does not work in the local server of the team lead's laptop as well. (That must mean that the team lead has older versions of development software installed).
Also, both the projects need to be completed within a month. Even though I asked my team lead to upgrade his software, which is free of cost, he isn't doing it. And he is asking me to do both projects.
What can I do in such a case?