The issue of students' difficulties in solving context-based mathematics problems has been extensively investigated by numerous studies. However, limited study focus on how pre-service primary school teacher (PSPSTs) encounter difficulties in solving context-based fundamental mathematics problems. To fill this gap, this study aims to investigate PSPSTs' difficulties encountered while solving context-based mathematics tasks by identifying the error type they made based on the error classification proposed in Newman Error Analysis (NEA). This is an error analysis study with a summative qualitative content analysis approach involving 87 PSPSTs in an Indonesian Islamic University. Data were collected through a test, in-depth interviews and document analysis of the PSPSTs' responses. Data were analyzed qualitatively and quantitatively. Qualitative content analysis was performed using Atlas.ti software. The findings revealed that many PSPSTs encounter difficulties in solving context-based problems. Approximately 22.1% of PSPSTs committed errors in comprehension, 17.5% each in reading and encoding, 14.7% in transformation, and 8.7% in process skill. Furthermore, the findings indicated a hierarchical structure in the occurrence of errors. Errors in the early stages have a high potential to cause errors in subsequent problem-solving stages. All the results are discussed, along with their implications for practice and suggestions for future research.