为何群组里发帖子时，不能上传其它附件，只能上传图片？如何解决？

http://data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAA5EAAAEaCAYAAACIOtONAAAgAElEQVR4Ae29B3hU16GuTZy/3Pv/9z7/Ofe0nOfee5Kcc3JvEvfYidMcJxg7Do4dl9g5tokLsR3ccME2zWCwARfcAJti0wymV9Gb6N1CEggQagiQhLpEB4HE9z9rz+zRntEezZY0kqa88zxbs8vaq7zr26P17bX22l3q6urEAgM0gAbQABpAA2gADaABNIAG0AAa8KKBLl4CEQYxoQE0gAbQABpAA2gADaABNIAG0IDRQJeCggKxwAANoAE0gAbQABpAA2gADaABNIAGvGigi/hAAAIQgAAEIAABCEAAAhCAAAQ8EsBEegRFMAhAAAIQgAAEIAABCEAAAhCQMJGoAAIQgAAEIAABCEAAAhCAAAQ8E8BEekZFQAhAAAIQgAAEIAABCEAAAhDARKIBCEAAAhCAAAQgAAEIQAACEPBMABPpGRUBIQABCEAAAhCAAAQgAAEIQAATiQYgAAEIQAACEIAABCAAAQhAwDMBTKRnVASEAAQgAAEIQAACEIAABCAAAUwkGoAABCAAAQhAAAIQgAAEIAABzwSiYiIvX77sOUECQgACEIAABCAAAQhAAAIQgEDnEmiLh2uViWxoaNCJEydUVFSkQ4cOad++fUpLS2OBARpAA2gADaABNIAG0AAaQANoIA40YDyc8XLG0xlvZzye10+LTeTJkydVUFCAMOJAGBh7bmygATSABtAAGkADaAANoAE04EUDxuMZr+fl0yITWV5eTq8j5pEbCGgADaABNIAG0AAaQANoAA0koAZM76TxfJE+nk1kRUWFMjIyEEsCisXLnQnCcAcLDaABNIAG0AAaQANoAA0kvgaM5zPer7mPJxNpxsjy3GPiC4YfBeoYDaABNIAG0AAaQANoAA2gAeP9jAcM9/FkInkGEiHxY4IG0AAaQANoAA2gATSABtBA8mjAeMBwn4gm0jjQPXv2MIyVYaxoAA2gATSABtAAGkADaAANoIEk0YDxgOF6IyOaSDPlK3cckueOA3VNXaMBNIAG0AAaQANoAA2gATRgNGC8oNsnook07w5BRIgIDaABNIAG0AAaQANoAA2gATSQXBowXtDtE9FEpqenYyKTpMuaH4Xk+lGgvqlvNIAG0AAaQANoAA2ggeY0YLyg2yeiiWwuUo4hOjSABtAAGkADaAANoAE0gAbQQOJqABNJjyK9ymgADaABNIAG0AAaQANoAA2gAc8a6BAT6ZYI+yAAAQhAAAIQgAAEIAABCECg8wm0tNfYLcdRH87qlgj7IAABCEAAAhCAAAQgAAEIQKDzCWAiO78OyAEEIAABCEAAAhCAAAQgAIG4IYCJjJuqIqMQgAAEIAABCEAAAhCAAAQ6nwAmsvPrgBxAAAIQgAAEIAABCEAAAhCIGwKYyLipKjIKAQhAAAIQgAAEIAABCECg8wlgIju/DsgBBCAAAQhAAAIQgAAEIACBuCGAiYybqiKjEIAABCAAAQhAAAIQgAAEOp8AJrLz64AcQAACEIAABCAAAQhAAAIQiBsCmMi4qSoyCgEIQAACEIAABCAAAQhAoPMJYCI7vw7IAQQgAAEIQAACEIAABCAAgbghgImMm6oioxCAAAQgAAEIQAACEIAABDqfACay8+uAHEAAAhCAAAQgAAEIQAACEIgbApjIuKkqMgoBCEAAAhCAAAQgAAEIQKDzCWAiO78OyAEEIAABCEAAAhCAAAQgAIG4IZBwJrKoqEgsscsgbq4MMgoBCEAAAhCAAAQgAAEIuBJISBPpWlJ2djoBY+75QAACEIAABCAAAQhAAAJNCdTV1enIkSPKyclpl8XEbdKIxgcTGQ2KxOGJACbSEyYCQQACEIAABCAAAQgkGQFj7kpLS7V+/XotW7asXRYTt0kjGkYSE5lkAu3M4mIiO5M+aUMAAhCAAAQgAAEIxCqBwsJCpaamWuZxyZIlao/FmFOThkmrrR9MZFsJcr5nAphIz6gICAEIQAACEIAABCCQRAQOHTqklJSUDllMWm39YCLbSpDzPRPARHpGRUAIQAACEIAABCAAgSQigIl0qexoOFWXaF13YVRcscTETuomJqqBTEAAAhCAAAQgAAEIxBiB7OxsLVq0qEMWk1ZbP9Hwd10iZSIaiURKwz6OUbFJxN43dRN7dUKOIAABCEAAAhCAAAQ6n4AxdgsXLuyQBRPpUt8YFRcoMbKLuomRiiAbEIAABCAAAQhAAAIxReDgwYNhDeTixYu1evVqrVu3zvo226GG00sY+xyTVls/0egkpCeyrbWQJOdjIpOkoikmBCAAAQhAAAIQgECLCBhjt2DBAtfFGMjjx4/r5MmT1rfZDg3rJYx9DibSpWowKi5QYmQXdRMjFUE2IAABCEAAAhCAAARiisCBAwc0f/5812XNmjWWgTQZvnDhggoKCrRp06ZAWLNu9plj5mPMpjknXHwmrbZ+6IlsK0HO90wAE+kZFQEhAAEIQAACEIAABJKIgDF28+bNc11WrlypkpKSgEk0WPLz862hraYH0qzbH2MkTVhzTrj4MJE2Lcd3exqVA5N6qMdjZhmiFRWORCOtnkjVkPt76LXh85RxwhH4WIpes+LrofG76hwHQlbPndbpE02XunoTrlQpL3RT9wd7aoZjeHP1qiG+vE5yudNQOE+9Xx2hGasOqNSKIzi9jFHd1K2bWcYoI/hQm7bas27alDFOhgAEIAABCEAAAhCAQCcSMMZu7ty5rovpUVyxYkUTs2h6HM1i90Ca7BtDacKac8LFh4l0qej2NCqN5qq3UspcEg+z6/TaAT5T1n2EtpxrDBTY3623UpoxpY3p2ubOfPvzcGyeehrDd/94HXAYwtJFvX1pjmpqA49O7+E3iQOUakxtxgwNGJei1IOlVuYa08NENtYWaxCAAAQgAAEIQAACEGgfAvv379ecOXOaXdavX6+8vLwg02jnxhhJc8yEiRSPSautH4aztoBgo7lqiYms05bhPvPXfVSGSu0ewsd66MG7bFPYXQ/6eyR9PZ2+Hs8hq6qt3AXSvetBq3fxnu6NJvLonJ6WIew552hQScKbyKOa96Q/P+9uken/DJhKY0SNp6QnMoglGxCAAAQgAAEIQAACEGhPAllZWZo9e3bExfQynjjhHNroy5XZZ455icOk1dYPJrIFBBvNVQtM5IlUDbCGht6j8VlSwNxZ+2wT6f7de1FIz6DpVTy3RSPsnkezbhnKbhqzZIWGOI3o/d19vY2W8XQMvy2coR5W2t01YquxkNVKecmf/qAVKj1xWqnv2vkZoVTnMFpHL2oLsAWCtmcvcSARViAAAQhAAAIQgAAEIBBnBIyxmzVrVsQlkon0Egcm0kUc7WlUWmMiq1e95jNzj82Q1VdY53+2MWO8HvQbySGrSl2feTztf0wykK4xkWlj1L1bN93z+QHZvZDm+cUxi1LUO6wxbTS9B8bd4x/K+qF2meGvtikNe65tKLupm8vQWJcqCLurPesmbKIcgAAEIAABCEAAAhCAQIwTMMZu5syZzS6pqanKzc0NO5zVHDNhIsWDiXQRQ3salYCZa85wOY1W/VHN8A8d7fZCikrr6wJmMW+O/5nFbr01r7DppDm+iXR8LjKQ7qhdyhhlehjv0fhdjb2Qlolcm6F5n47RGP/y4Ut+s/jEAI351D+hj6Pn0p40p27rCMuU+ibScRhGtzI6y+bCPtKu9qybSGlzHAIQgAAEIAABCEAAArFKYN++fWHNnxmiumTJEstA2vk/f/68NazVDGM16/bHGEkT1pwTzkyatNr6YThrCwgGzJybwbL3OYzW6U0Og2ZMZNoYfy9gBLNmx+WfHTWQ7qjxGn+/mURnjCZ/avco+uIakyapvk7VJ3zGMzBs1pGfQK+oFb+ZNKdOW971D3t9crIO+IeuMpy1BaIgKAQgAAEIQAACEIAABNpIwBi7r776ynVJSUmR6YxxmsWcnBwtXbrUWsy6/TFhTFhzTrj4MJE2Lcd3e/Z2Bcxct3vUe2Rjr5/d+2d9r/VPcOPshTSmzZjIrMm+12486Ddu3cyrOezXhrh9Tw6e6OavvdTLxPXQeO1aP0Ld7++t3o/5TeTnk/WgeT6y7wqZ6XiamMjQ/BiD6uiZdE7M01hOZmd1SItVCEAAAhCAAAQgAAEItAuBvXv3avr06a6LMYv2ZDrGJBrTuGbNmkBYs2722SbThDXnhIvPpNXWDz2RLSDYaK4anzEMd7oZJho0RNSYSH/gxh7ByPGYUwLpjtqijFG+Hsjei7boQFae9Y5IazjrJnt4qy/OJiYyw/csZWOexiijvk6lOyZrQI8BWuGbCNbKYSA93hMZrnrZDwEIQAACEIAABCAAgagRaM5ELlq0SMeOHVNtba31bbZDDaKXMPY5mEiXauuYnkgP5s+aBbW7BgzwT6wTMJGnlTrAP5z1nl4a4XiOMahH89MxSi30FTBg6szQ1OoVes30RloT9ZQ2msi0xqGpplexiYksmWf1Yj740IN+cztGGSeCn6O00x/whD3ctqcGBOXP/2ylC3cvu9qzbrykTxgIQAACEIAABCAAAQjEIoHMzEx9+eWXrosZlrpw4UJriKr5NtuhYb2Esc8xabX1Q09kCwgGzFw3DybSDBV9coaO7vI/BxkwkY3Gr7FX0DZtwd/Wc45BPZEZZqCq5v3VhDN5aIzLhK3b5O/9fDZFuxb5J+4JPBOZoTH3f6hd6+3nMscoo6y5GV2D8+LLq4dyN8MTE9kMHA5BAAIQgAAEIAABCCQtAWPspk6d2iELJtJFZu1pVFpkIlWq0hJZr+SwDFjARNapNGOXdu1ouqR+2rNxCOxDY5Rx2lfAQLqWIWzsyRyTFmwida5Uefm+calNeiJ1WqUlpxvzY4aqVoS8W9L/nskH77INZHc96Hz35GOO9026sI+0qz3rJlLaHIcABCAAAQhAAAIQgECsEsjIyOgQA2mMqkmrrR96IltAMGDmvPRE2vHaM7IGTKSkshUaMWiyUv2GzwQ9nTVevczEONbEOY0G0hwLpPvSGKUuGuMP10MzCkNMpJ2m28Q69jE7P8087xhIr5kwdnQt+cZEtoQWYSEAAQhAAAIQgAAEkoWAMXaTJ0/ukAUT6aKq9jQqjeaqBcM6bdMWMJHVSh3gmJ31/t76cNwQ9XAYyF0nggsWSHf4CI0wJtM/Q+uBekxkMCm2IAABCEAAAhCAAAQgEH8E0tPTNWnSpA5ZTFpt/dATGUqwxc8J2kM/Hd8Bw+g2nFWqzk/V5EE91d02hIHvHvpwh2OaVH/eAiZy1AylmoluZqbqqGU0Q0xkvf+E+mqlDvcb1cAzkf5jtqltppcxkF4zYUKxedluT4PvJX3CQAACEIAABCAAAQhAIBYJHDx4UPPmzbOGtLaXmTRDWU0aJq22fjCRoQQ7wEQGkqwrVcacEeoZeAbRZ0S7PzFZGXWBUI3DWUMNoUJMpJnMJ2BIfXH1XmS/WMQfHyayESxrEIAABCAAAQhAAAIQiAEC5h2PR48e1dy5czVx4sR2WUzcJg37fZJtKTYmMpTeuVJluEx64zYRTth9GaUKeEDbtDl7J0PTNO9rTJunEU/4eg8f/PxAUIhAz2AkExmYudVvRnsEP1tpRWrnp5lexkB6zYQJyqDHDXoiPYIiGAQgAAEIQAACEIBA0hEw5s70Eu7Zs6ddFhN3NAykqRhMZHvLszrPNxOr01g2k2Z1fp5KzwUHqM73z+TqmIjHF6Jxptc8/yjYutOndfrEaZ0OuNjguGTnZ0eemg6c9YUNpNdMmJBYPW1iIj1hIhAEIAABCEAAAhCAAARimgAmMqarJ7Eyh4lMrPqkNBCAAAQgAAEIQAACyUkAE5mc9d4ppcZEdgp2EoUABCAAAQhAAAIQgEBUCWAio4qTyJojgIlsjg7HIAABCEAAAhCAAAQgEB8EMJHxUU8JkUtMZEJUI4WAAAQgAAEIQAACEEhyApjIJBdARxYfE9mRtEkLAhCAAAQgAAEIQAAC7UMAE9k+XInVhQAm0gUKuyAAAQhAAAIQgAAEIBBnBDCRcVZh8ZxdTGQ81x55hwAEIAABCEAAAhCAgI8AJhIldBgBTGSHoSYhCEAAAhCAAAQgAAEItBsBTGS7oSXiUAKYyFAibEMAAhCAAAQgAAEIQCD+CMSkiTRmoy1L/FVDcuS4LXXKuW27JuAHPzSABtAAGkADaAANoIFoaSAmTWRbLNXJkyfbcjrntiMB6qYd4RI1BCAAAQhAAAIQgAAEOohAwpnIDuJGMhCAAAQgAAEIQAACEIAABJKSACYyKaudQkMAAhCAAAQgAAEIQAACEGgdAUxk67hxFgQgAAEIQAACEIAABCAAgaQkgIlMymqn0BCAAAQgAAEIQAACEIAABFpHABPZOm6cBQEIQAACEIAABCAAAQhAICkJYCKTstopNAQgAAEIQAACEIAABCAAgdYRwES2jhtnQQACEIAABCAAAQhAAAIQSEoCmMikrHYKDQEIQAACEIAABCAAAQhAoHUEMJGt48ZZEIAABCAAAQhAAAIQgAAEkpIAJjIpq51CQwACEIAABCAAAQhAAAIQaB0BTGTruHEWBCAAAQhAAAIQgAAEIACBpCSAiUzKaqfQEIAABCAAAQhAAAIQgAAEWkcAE9k6bpwFAQhAAAIQgAAEIAABCEAgKQlgIpOy2ik0BCAAAQhAAAIQgAAEIACB1hHARLaOG2dBAAIQgAAEIAABCEAAAhBISgIJZyJzKuu0YX+Jpq3dp/HLszR26X4WGLRIA0Y3Rj9GR0ZPfCAAAQhAAAIQgAAEIACBRgIJZyKn7CxX3692685BC/SL11L0kz5L4mK5qc8S/ezV5FhMWWO5XoxujH6Mjoye+EAAAhCAAAQgAAEIQAACjQQSzkTeOXSN/jx6p16eeUh9Fx1WvyVH4mIZtOyohq86lhSLKWss14vRjdGP0ZHREx8IQAACEIAABCAAAQhAoJFAwpnIq5+Zqz+N2qWha8o1cG2lBqyLj2VQapXe3uhb3tlcrQ+31STUYspkl2/Q+qqYrhejG6MfoyOjJz4QgAAEIAABCEAAAhCAQCOBhDOR339qth7+7GuN2Fyt55eV66mUsrhbXlhern5rK62l/9oqDVwXn4vJu10OU6Z4qQujG6MfoyOjJz4QgAAEIAABCEAAAhCAQCMBTGQMmsy/LinTs0vLreWllRVxayJfXlkRKIcpEyay8cJjDQIQgAAEIAABCEAAAvFKICFN5INjdmvIhio9F6c9kU6zZcykMWP28srKCqt3L9Z6J02Po8mbnU/bQDrLEi/rRjdGP0ZH9ETG608b+YYABCAAAQhAAAIQaC8CCWki7/1kt/quqZTp/frL4rYtxvi8uKJMzy0LH48J0ztMmFDj9OyyMr28sly9lpbJrL+yqrzZ5YXlwT14T6eUqc+qCpmhoqHLWxuqZBbzTF/Q4nE47OD1VRq+qUpvrncfPmvFv9F3bEBI+iZPJm+h5TXlNOU1ZQ091pJtE89LJp6lwfXw9BKz3/TcBu9vS70b3Rj9GB1hItvrp4d4IQABCEAAAhCAAATilUDCmsjXVlfqz/OO60+zS9q0PLXouJbkVGrc7vKw8fxl4XEtPlSpCV9XBIX5jzklemJRaZB5+nhHhbYcq9aQDeX6aHuFvj5e3ezy1b7KoPON8XrGDHVdFryYZw5Tcqq15GClBiw5HrQMXO1tSOzY3dXKKKvRhLRq1yG0Jv6VeTUyZtPqaXTkweTJzRQO3VCubUXV+nB7hetxt3Pc9g1KLdemo9V6f0twPby8olTrC6s0cmvw/rbUu9GN0Q8mMl5/1sg3BCAAAQhAAAIQgEB7EkhYE/nqqko9NKdE980obtPy53kl+jytXF9mVOj9LWV6fL4vzodmF+vtDaV6bdVx9VxQol3FVZrx9WH9dtRu/WFqgZXm/TOL9fDc4/rz/MZl/NcVOnaySkOWHNDgZTlaXVClwydqtK+oSHO2ZAaWBdv3Krf8uJbtP6qHvtijJ+YeadaEmd6zSemVSjlYqdlpZXpvXZkGLCu1loFrHCZyVYUGrix3XaakVarqfK0+25CjgYsPaXZWtUZua+yV3HKsRlsPl+i56Rl6at7hZvNjG8H3t1ao5EytxmzIVY+pWXpy0fGw5z2+sDSIlZPbm+vLLE4fp+bojk/Tde/0oxbjV1ceV15tjUat9+2/Z9qRNtW30YvRjdEPJrI9f3qIGwIQgAAEIAABCEAgXglgIj2azDE7y7WvvFovLy2yDEzPhSXaXVKlhQcr9NyS41Zv4rRN6eo6eI4emHJA/zHb3byO3lGmIzXlenn8Ct330Xo9v7xMG49Wae62fbr3zVm6841ZumvQLD08Yp7WZuVq9ta9umPADPWYuj9gvszQWjN81m35Yk+lKs/X6qt91XprY1XTZVWp3lxSrP6Lghez78udZSo6VaPB01L1xtQ1qjhbrS/TK9RvdZk1dNaYyLV7D+muN2bo4YnpgfzYhtHt2zaR787dqD+MWK6e84v05OIy1+Whue6m37B8Y22pDlRW652FW3X7sCV6aMZh9ZhbokHrSlVQW6MPl2zT7cNS9NBXBfrTLHf2Xm8oYCLj9eeMfEMAAhCAAAQgAAEIdAQBTKRHE/nUohK9vvyoun+Qqts+2SnbRObW1Gh7UZWKTtcou6xEa/bnamNBqYzpdDMtxkQW1pSr12fLdNu7a/Xw3BL1WXlc47Yd0+q9Oeq36KDeXp6tdVl5mrCrRC/PSg8ykc8sLdPcA5XaUVztuhyorFHVhVplV9doT6nLUlKt+fsq9Nzi0qBl3r4Krcqt1MhtFXps9NqAiRyZ8rV6jNtuPXO4vrC6TSbyzmHL9OCMo0FDfp3DTv840938GWZLDlVq2MZSTdlZqLUHC7SpsEKbj1Yp7Xi1ys7Wam9RkdYe8O0fvrHMlb1bfbjtw0R2xE8PaUAAAhCAAAQgAAEIxCsBTKRHE2nMxj1fFurWkZv1xJfpGrWjTHP2V2h+RqEW7MpSflWZ0o8d08ytmdYyaOEe/Xb019bQVtNT+eG2MmtZnlup4lOVGr9mt579ak/A7PRbXarF2ZWamlGp6XsrNf9AuV6Yu1/3fbpd93+8QY/PyrN6/swEM1MzK7X8wDEt3pllDXk9eLxYC3bsdV0W7tinnLISZZeWBI6PWpXpGyI7pzDQm2gM4vrcYj0yMV0PjN6stxftUcW5Gs3blqkPlu7RhK/LlV5WrfQjR/X+vE0avSFPE9IqraXfWvfnIU3PpN0TOWz2BnUbulT3TisMlNnNwLntm7u/QtuPHNefvtijt1fna9H+Es3anqX0o0dVUFWmhbuzAtwN/1dmp+l3n2WotUNbMZHx+nNGviEAAQhAAAIQgAAEOoJAgprIXXp1VYUeml2i+74qbvXywMxia1iqGU5plj/NLtb9M4o1ZkeZsiur1Wd5sbp9uE2/fXO2Nh8q0KT1abrhpcm68eWp1nLT6zPVfXyWPtleptIzNTp+ukrlZ6utnsKyM9Wam1Xqe7bvqyKZXrjHF5Ro45EqLcqutHrsfjV0mX77/jrXoZ8PT8ywhr2u3ZejlF1Z+m3fabqj/1e6o/+MoKX7wJlalZGtZWn7fWH6NYZ5ZPJeawZbM3PqxiPVWpVxUL