What are the common pitfalls and challenges of evaluating a prototype with stakeholders?

I think identifying your stakeholders and the expectations should be the first step. That allows you to prepare the prototype and an evaluation plan. Assuming stakeholders are identified, this section is is good. The last sentence needs some updates though in terms of structure.

In my opinion the success of a prototype or MVP relies on two key elements: a thorough understanding of the end product and a well-defined roadmap. With a clear vision, prioritize essential functionalities in the MVP, engaging core users who become fervent advocates. Ensure they grasp the overarching strategy. After delivering the prototype, collect valuable quantitative and qualitative data, refining and developing the remaining product aspects, ultimately creating a solution that resonates with your audience.

Whether the prototype is of high fidelity or low fidelity, one common pitfall when presenting it is that your audience may find it to either look “too real” or “unfinished”. One way around this is to communicate the intention of the prototype upfront by the either stating to your audience that it is for conversation and feedback, not evaluating a particular solution or “how” something will be done.

You should also consider the level of involvement needed: Think about the level of involvement that each stakeholder will need in the evaluation of the features or functionalities. For example, you may want to involve end-users in the evaluation process to get feedback on usability and functionality, but they may not need to be involved in the technical aspects of the evaluation.

You could also make it interesting and invite stakeholders who know nothing about this to see how they use the prototype! (Not critical but it’s a bonus tip)

One thing I have found helpful is providing the “WHY” behind the design prototype and the business context. It ensures stakeholders are aligned and sets the right expectations.

To get good feedback, include a mix of open ended and specific questions - and tie these to the evaluation criteria and the expected outcome of the prototype

Feedback doesn't always have to be data driven. Be open to assessing qualitative feedback through the lens of empathy which will be your unique differentiator.

Creating frequent, dedicated channels of communication to keep stakeholders informed on the project's progress is key to success. In addition, this opens the door to feedback loops.